study/ZiuChen.github.io
1
0
Fork 0
mirror of https://github.com/ZiuChen/ZiuChen.github.io.git synced 2025-08-18 23:49:33 +08:00
Code Issues Packages Projects Releases Wiki Activity
ZiuChen.github.io/note/Redux.html

669 lines
287 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en-US" dir="ltr">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>Redux | ZiuChen</title>
<meta name="description" content="Unlimited Progress.">
<link rel="preload stylesheet" href="/assets/style.10d30366.css" as="style">
<script type="module" src="/assets/app.bdd8a2bd.js"></script>
<link rel="preload" href="/assets/inter-roman-latin.2ed14f66.woff2" as="font" type="font/woff2" crossorigin="">
<link rel="modulepreload" href="/assets/chunks/framework.a304f0f7.js">
<link rel="modulepreload" href="/assets/chunks/theme.f2bdac91.js">
<link rel="modulepreload" href="/assets/note_Redux.md.df821c9b.lean.js">
<link rel="icon" href="/logo.png">
<script id="check-dark-light">(()=>{const e=localStorage.getItem("vitepress-theme-appearance")||"",a=window.matchMedia("(prefers-color-scheme: dark)").matches;(!e||e==="auto"?a:e==="dark")&&document.documentElement.classList.add("dark")})();</script>
</head>
<body>
<div id="app"><div class="Layout" data-v-6305e88a><!--[--><!--]--><!--[--><span tabindex="-1" data-v-4dd3ce25></span><a href="#VPContent" class="VPSkipLink visually-hidden" data-v-4dd3ce25> Skip to content </a><!--]--><!----><header class="VPNav" data-v-6305e88a data-v-a35c4512><div class="VPNavBar has-sidebar" data-v-a35c4512 data-v-177342c2><div class="container" data-v-177342c2><div class="title" data-v-177342c2><div class="VPNavBarTitle has-sidebar" data-v-177342c2 data-v-aca9ebf6><a class="title" href="/" data-v-aca9ebf6><!--[--><!--]--><!--[--><img class="VPImage logo" src="/logo.png" alt data-v-5113f303><!--]--><!--[-->ZiuChen<!--]--><!--[--><!--]--></a></div></div><div class="content" data-v-177342c2><div class="curtain" data-v-177342c2></div><div class="content-body" data-v-177342c2><!--[--><!--]--><div class="VPNavBarSearch search" style="--vp-meta-key:&#39;Meta&#39;;" data-v-177342c2><!--[--><div id="docsearch"><button type="button" class="DocSearch DocSearch-Button" aria-label="Search"><span class="DocSearch-Button-Container"><svg class="DocSearch-Search-Icon" width="20" height="20" viewBox="0 0 20 20" aria-label="search icon"><path d="M14.386 14.386l4.0877 4.0877-4.0877-4.0877c-2.9418 2.9419-7.7115 2.9419-10.6533 0-2.9419-2.9418-2.9419-7.7115 0-10.6533 2.9418-2.9419 7.7115-2.9419 10.6533 0 2.9419 2.9418 2.9419 7.7115 0 10.6533z" stroke="currentColor" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"></path></svg><span class="DocSearch-Button-Placeholder">Search</span></span><span class="DocSearch-Button-Keys"><kbd class="DocSearch-Button-Key"></kbd><kbd class="DocSearch-Button-Key">K</kbd></span></button></div><!--]--></div><nav aria-labelledby="main-nav-aria-label" class="VPNavBarMenu menu" data-v-177342c2 data-v-0725df7f><span id="main-nav-aria-label" class="visually-hidden" data-v-0725df7f>Main Navigation</span><!--[--><!--[--><a class="VPLink link VPNavBarMenuLink" href="/" tabindex="0" data-v-0725df7f data-v-54fa8d63 data-v-fd6e3585><!--[-->首页<!--]--><!----></a><!--]--><!--[--><div class="VPFlyout VPNavBarMenuGroup" data-v-0725df7f data-v-93bf11df><button type="button" class="button" aria-haspopup="true" aria-expanded="false" data-v-93bf11df><span class="text" data-v-93bf11df><!----> 我的项目 <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="text-icon" data-v-93bf11df><path d="M12,16c-0.3,0-0.5-0.1-0.7-0.3l-6-6c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l5.3,5.3l5.3-5.3c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-6,6C12.5,15.9,12.3,16,12,16z"></path></svg></span></button><div class="menu" data-v-93bf11df><div class="VPMenu" data-v-93bf11df data-v-fb66cf11><div class="items" data-v-fb66cf11><!--[--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/project/ClipboardManager/" data-v-504c1659 data-v-fd6e3585><!--[-->超级剪贴板<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/project/Markdown/" data-v-504c1659 data-v-fd6e3585><!--[-->超级Markdown<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/project/JSRunner/" data-v-504c1659 data-v-fd6e3585><!--[-->超级JavaScript<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/project/SmartWordBreak/" data-v-504c1659 data-v-fd6e3585><!--[-->超级分词<!--]--><!----></a></div><!--]--><!--]--></div><!--[--><!--]--></div></div></div><!--]--><!--[--><div class="VPFlyout VPNavBarMenuGroup" data-v-0725df7f data-v-93bf11df><button type="button" class="button" aria-haspopup="true" aria-expanded="false" data-v-93bf11df><span class="text" data-v-93bf11df><!----> 开源作品 <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="text-icon" data-v-93bf11df><path d="M12,16c-0.3,0-0.5-0.1-0.7-0.3l-6-6c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l5.3,5.3l5.3-5.3c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-6,6C12.5,15.9,12.3,16,12,16z"></path></svg></span></button><div class="menu" data-v-93bf11df><div class="VPMenu" data-v-93bf11df data-v-fb66cf11><div class="items" data-v-fb66cf11><!--[--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/works/opensource.html" data-v-504c1659 data-v-fd6e3585><!--[-->个人作品<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/works/contribution.html" data-v-504c1659 data-v-fd6e3585><!--[-->社区贡献<!--]--><!----></a></div><!--]--><!--]--></div><!--[--><!--]--></div></div></div><!--]--><!--[--><div class="VPFlyout VPNavBarMenuGroup" data-v-0725df7f data-v-93bf11df><button type="button" class="button" aria-haspopup="true" aria-expanded="false" data-v-93bf11df><span class="text" data-v-93bf11df><!----> 学习笔记 <svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="text-icon" data-v-93bf11df><path d="M12,16c-0.3,0-0.5-0.1-0.7-0.3l-6-6c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l5.3,5.3l5.3-5.3c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-6,6C12.5,15.9,12.3,16,12,16z"></path></svg></span></button><div class="menu" data-v-93bf11df><div class="VPMenu" data-v-93bf11df data-v-fb66cf11><div class="items" data-v-fb66cf11><!--[--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/JavaScript.html" data-v-504c1659 data-v-fd6e3585><!--[-->JavaScript基础<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/CSS.html" data-v-504c1659 data-v-fd6e3585><!--[-->CSS基础<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/JavaScriptEnhanced.html" data-v-504c1659 data-v-fd6e3585><!--[-->JavaScript进阶<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/Front-end%20Engineering.html" data-v-504c1659 data-v-fd6e3585><!--[-->前端工程化<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/SSR.html" data-v-504c1659 data-v-fd6e3585><!--[-->服务端渲染<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/React.html" data-v-504c1659 data-v-fd6e3585><!--[-->React基础<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/React%20Hooks.html" data-v-504c1659 data-v-fd6e3585><!--[-->React Hooks<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link active" href="/note/Redux.html" data-v-504c1659 data-v-fd6e3585><!--[-->Redux<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/React%20Router.html" data-v-504c1659 data-v-fd6e3585><!--[-->React Router<!--]--><!----></a></div><!--]--><!--[--><div class="VPMenuLink" data-v-fb66cf11 data-v-504c1659><a class="VPLink link" href="/note/MySQL.html" data-v-504c1659 data-v-fd6e3585><!--[-->MySQL<!--]--><!----></a></div><!--]--><!--]--></div><!--[--><!--]--></div></div></div><!--]--><!--[--><a class="VPLink link VPNavBarMenuLink" href="/self/" tabindex="0" data-v-0725df7f data-v-54fa8d63 data-v-fd6e3585><!--[-->个人介绍<!--]--><!----></a><!--]--><!--]--></nav><!----><div class="VPNavBarAppearance appearance" data-v-177342c2 data-v-140d7008><label title="toggle dark mode" data-v-140d7008 data-v-69cfd7b7><button class="VPSwitch VPSwitchAppearance" type="button" role="switch" aria-checked="false" data-v-69cfd7b7 data-v-2a85d626><span class="check" data-v-2a85d626><span class="icon" data-v-2a85d626><!--[--><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="sun" data-v-69cfd7b7><path d="M12,18c-3.3,0-6-2.7-6-6s2.7-6,6-6s6,2.7,6,6S15.3,18,12,18zM12,8c-2.2,0-4,1.8-4,4c0,2.2,1.8,4,4,4c2.2,0,4-1.8,4-4C16,9.8,14.2,8,12,8z"></path><path d="M12,4c-0.6,0-1-0.4-1-1V1c0-0.6,0.4-1,1-1s1,0.4,1,1v2C13,3.6,12.6,4,12,4z"></path><path d="M12,24c-0.6,0-1-0.4-1-1v-2c0-0.6,0.4-1,1-1s1,0.4,1,1v2C13,23.6,12.6,24,12,24z"></path><path d="M5.6,6.6c-0.3,0-0.5-0.1-0.7-0.3L3.5,4.9c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l1.4,1.4c0.4,0.4,0.4,1,0,1.4C6.2,6.5,5.9,6.6,5.6,6.6z"></path><path d="M19.8,20.8c-0.3,0-0.5-0.1-0.7-0.3l-1.4-1.4c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l1.4,1.4c0.4,0.4,0.4,1,0,1.4C20.3,20.7,20,20.8,19.8,20.8z"></path><path d="M3,13H1c-0.6,0-1-0.4-1-1s0.4-1,1-1h2c0.6,0,1,0.4,1,1S3.6,13,3,13z"></path><path d="M23,13h-2c-0.6,0-1-0.4-1-1s0.4-1,1-1h2c0.6,0,1,0.4,1,1S23.6,13,23,13z"></path><path d="M4.2,20.8c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l1.4-1.4c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-1.4,1.4C4.7,20.7,4.5,20.8,4.2,20.8z"></path><path d="M18.4,6.6c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l1.4-1.4c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-1.4,1.4C18.9,6.5,18.6,6.6,18.4,6.6z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="moon" data-v-69cfd7b7><path d="M12.1,22c-0.3,0-0.6,0-0.9,0c-5.5-0.5-9.5-5.4-9-10.9c0.4-4.8,4.2-8.6,9-9c0.4,0,0.8,0.2,1,0.5c0.2,0.3,0.2,0.8-0.1,1.1c-2,2.7-1.4,6.4,1.3,8.4c2.1,1.6,5,1.6,7.1,0c0.3-0.2,0.7-0.3,1.1-0.1c0.3,0.2,0.5,0.6,0.5,1c-0.2,2.7-1.5,5.1-3.6,6.8C16.6,21.2,14.4,22,12.1,22zM9.3,4.4c-2.9,1-5,3.6-5.2,6.8c-0.4,4.4,2.8,8.3,7.2,8.7c2.1,0.2,4.2-0.4,5.8-1.8c1.1-0.9,1.9-2.1,2.4-3.4c-2.5,0.9-5.3,0.5-7.5-1.1C9.2,11.4,8.1,7.7,9.3,4.4z"></path></svg><!--]--></span></span></button></label></div><div class="VPSocialLinks VPNavBarSocialLinks social-links" data-v-177342c2 data-v-598000f3 data-v-efa5999f><!--[--><a class="VPSocialLink" href="https://github.com/ZiuChen" aria-label="github" target="_blank" rel="noopener" data-v-efa5999f data-v-88a75067><svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>GitHub</title><path d="M12 .297c-6.63 0-12 5.373-12 12 0 5.303 3.438 9.8 8.205 11.385.6.113.82-.258.82-.577 0-.285-.01-1.04-.015-2.04-3.338.724-4.042-1.61-4.042-1.61C4.422 18.07 3.633 17.7 3.633 17.7c-1.087-.744.084-.729.084-.729 1.205.084 1.838 1.236 1.838 1.236 1.07 1.835 2.809 1.305 3.495.998.108-.776.417-1.305.76-1.605-2.665-.3-5.466-1.332-5.466-5.93 0-1.31.465-2.38 1.235-3.22-.135-.303-.54-1.523.105-3.176 0 0 1.005-.322 3.3 1.23.96-.267 1.98-.399 3-.405 1.02.006 2.04.138 3 .405 2.28-1.552 3.285-1.23 3.285-1.23.645 1.653.24 2.873.12 3.176.765.84 1.23 1.91 1.23 3.22 0 4.61-2.805 5.625-5.475 5.92.42.36.81 1.096.81 2.22 0 1.606-.015 2.896-.015 3.286 0 .315.21.69.825.57C20.565 22.092 24 17.592 24 12.297c0-6.627-5.373-12-12-12"/></svg></a><a class="VPSocialLink" href="https://juejin.cn/user/1887205216238477" aria-label target="_blank" rel="noopener" data-v-efa5999f data-v-88a75067><svg width="36" height="28" viewBox="0 0 36 28" fill="none" xmlns="http://www.w3.org/2000/svg"><path fill-rule="evenodd" clip-rule="evenodd" d="M17.5875 6.77268L21.8232 3.40505L17.5875 0.00748237L17.5837 0L13.3555 3.39757L17.5837 6.76894L17.5875 6.77268ZM17.5863 17.3955H17.59L28.5161 8.77432L25.5526 6.39453L17.59 12.6808H17.5863L17.5825 12.6845L9.61993 6.40201L6.66016 8.78181L17.5825 17.3992L17.5863 17.3955ZM17.5828 23.2891L17.5865 23.2854L32.2133 11.7456L35.1768 14.1254L28.5238 19.3752L17.5865 28L0.284376 14.3574L0 14.1291L2.95977 11.7531L17.5828 23.2891Z" fill="#1E80FF"/></svg></a><!--]--></div><div class="VPFlyout VPNavBarExtra extra" data-v-177342c2 data-v-4ef5f3a8 data-v-93bf11df><button type="button" class="button" aria-haspopup="true" aria-expanded="false" aria-label="extra navigation" data-v-93bf11df><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="icon" data-v-93bf11df><circle cx="12" cy="12" r="2"></circle><circle cx="19" cy="12" r="2"></circle><circle cx="5" cy="12" r="2"></circle></svg></button><div class="menu" data-v-93bf11df><div class="VPMenu" data-v-93bf11df data-v-fb66cf11><!----><!--[--><!--[--><!----><div class="group" data-v-4ef5f3a8><div class="item appearance" data-v-4ef5f3a8><p class="label" data-v-4ef5f3a8>Appearance</p><div class="appearance-action" data-v-4ef5f3a8><label title="toggle dark mode" data-v-4ef5f3a8 data-v-69cfd7b7><button class="VPSwitch VPSwitchAppearance" type="button" role="switch" aria-checked="false" data-v-69cfd7b7 data-v-2a85d626><span class="check" data-v-2a85d626><span class="icon" data-v-2a85d626><!--[--><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="sun" data-v-69cfd7b7><path d="M12,18c-3.3,0-6-2.7-6-6s2.7-6,6-6s6,2.7,6,6S15.3,18,12,18zM12,8c-2.2,0-4,1.8-4,4c0,2.2,1.8,4,4,4c2.2,0,4-1.8,4-4C16,9.8,14.2,8,12,8z"></path><path d="M12,4c-0.6,0-1-0.4-1-1V1c0-0.6,0.4-1,1-1s1,0.4,1,1v2C13,3.6,12.6,4,12,4z"></path><path d="M12,24c-0.6,0-1-0.4-1-1v-2c0-0.6,0.4-1,1-1s1,0.4,1,1v2C13,23.6,12.6,24,12,24z"></path><path d="M5.6,6.6c-0.3,0-0.5-0.1-0.7-0.3L3.5,4.9c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l1.4,1.4c0.4,0.4,0.4,1,0,1.4C6.2,6.5,5.9,6.6,5.6,6.6z"></path><path d="M19.8,20.8c-0.3,0-0.5-0.1-0.7-0.3l-1.4-1.4c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l1.4,1.4c0.4,0.4,0.4,1,0,1.4C20.3,20.7,20,20.8,19.8,20.8z"></path><path d="M3,13H1c-0.6,0-1-0.4-1-1s0.4-1,1-1h2c0.6,0,1,0.4,1,1S3.6,13,3,13z"></path><path d="M23,13h-2c-0.6,0-1-0.4-1-1s0.4-1,1-1h2c0.6,0,1,0.4,1,1S23.6,13,23,13z"></path><path d="M4.2,20.8c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l1.4-1.4c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-1.4,1.4C4.7,20.7,4.5,20.8,4.2,20.8z"></path><path d="M18.4,6.6c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l1.4-1.4c0.4-0.4,1-0.4,1.4,0s0.4,1,0,1.4l-1.4,1.4C18.9,6.5,18.6,6.6,18.4,6.6z"></path></svg><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="moon" data-v-69cfd7b7><path d="M12.1,22c-0.3,0-0.6,0-0.9,0c-5.5-0.5-9.5-5.4-9-10.9c0.4-4.8,4.2-8.6,9-9c0.4,0,0.8,0.2,1,0.5c0.2,0.3,0.2,0.8-0.1,1.1c-2,2.7-1.4,6.4,1.3,8.4c2.1,1.6,5,1.6,7.1,0c0.3-0.2,0.7-0.3,1.1-0.1c0.3,0.2,0.5,0.6,0.5,1c-0.2,2.7-1.5,5.1-3.6,6.8C16.6,21.2,14.4,22,12.1,22zM9.3,4.4c-2.9,1-5,3.6-5.2,6.8c-0.4,4.4,2.8,8.3,7.2,8.7c2.1,0.2,4.2-0.4,5.8-1.8c1.1-0.9,1.9-2.1,2.4-3.4c-2.5,0.9-5.3,0.5-7.5-1.1C9.2,11.4,8.1,7.7,9.3,4.4z"></path></svg><!--]--></span></span></button></label></div></div></div><div class="group" data-v-4ef5f3a8><div class="item social-links" data-v-4ef5f3a8><div class="VPSocialLinks social-links-list" data-v-4ef5f3a8 data-v-efa5999f><!--[--><a class="VPSocialLink" href="https://github.com/ZiuChen" aria-label="github" target="_blank" rel="noopener" data-v-efa5999f data-v-88a75067><svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>GitHub</title><path d="M12 .297c-6.63 0-12 5.373-12 12 0 5.303 3.438 9.8 8.205 11.385.6.113.82-.258.82-.577 0-.285-.01-1.04-.015-2.04-3.338.724-4.042-1.61-4.042-1.61C4.422 18.07 3.633 17.7 3.633 17.7c-1.087-.744.084-.729.084-.729 1.205.084 1.838 1.236 1.838 1.236 1.07 1.835 2.809 1.305 3.495.998.108-.776.417-1.305.76-1.605-2.665-.3-5.466-1.332-5.466-5.93 0-1.31.465-2.38 1.235-3.22-.135-.303-.54-1.523.105-3.176 0 0 1.005-.322 3.3 1.23.96-.267 1.98-.399 3-.405 1.02.006 2.04.138 3 .405 2.28-1.552 3.285-1.23 3.285-1.23.645 1.653.24 2.873.12 3.176.765.84 1.23 1.91 1.23 3.22 0 4.61-2.805 5.625-5.475 5.92.42.36.81 1.096.81 2.22 0 1.606-.015 2.896-.015 3.286 0 .315.21.69.825.57C20.565 22.092 24 17.592 24 12.297c0-6.627-5.373-12-12-12"/></svg></a><a class="VPSocialLink" href="https://juejin.cn/user/1887205216238477" aria-label target="_blank" rel="noopener" data-v-efa5999f data-v-88a75067><svg width="36" height="28" viewBox="0 0 36 28" fill="none" xmlns="http://www.w3.org/2000/svg"><path fill-rule="evenodd" clip-rule="evenodd" d="M17.5875 6.77268L21.8232 3.40505L17.5875 0.00748237L17.5837 0L13.3555 3.39757L17.5837 6.76894L17.5875 6.77268ZM17.5863 17.3955H17.59L28.5161 8.77432L25.5526 6.39453L17.59 12.6808H17.5863L17.5825 12.6845L9.61993 6.40201L6.66016 8.78181L17.5825 17.3992L17.5863 17.3955ZM17.5828 23.2891L17.5865 23.2854L32.2133 11.7456L35.1768 14.1254L28.5238 19.3752L17.5865 28L0.284376 14.3574L0 14.1291L2.95977 11.7531L17.5828 23.2891Z" fill="#1E80FF"/></svg></a><!--]--></div></div></div><!--]--><!--]--></div></div></div><!--[--><!--]--><button type="button" class="VPNavBarHamburger hamburger" aria-label="mobile navigation" aria-expanded="false" aria-controls="VPNavScreen" data-v-177342c2 data-v-432ccc50><span class="container" data-v-432ccc50><span class="top" data-v-432ccc50></span><span class="middle" data-v-432ccc50></span><span class="bottom" data-v-432ccc50></span></span></button></div></div></div></div><!----></header><div class="VPLocalNav" data-v-6305e88a data-v-756dcc9b><button class="menu" aria-expanded="false" aria-controls="VPSidebarNav" data-v-756dcc9b><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="menu-icon" data-v-756dcc9b><path d="M17,11H3c-0.6,0-1-0.4-1-1s0.4-1,1-1h14c0.6,0,1,0.4,1,1S17.6,11,17,11z"></path><path d="M21,7H3C2.4,7,2,6.6,2,6s0.4-1,1-1h18c0.6,0,1,0.4,1,1S21.6,7,21,7z"></path><path d="M21,15H3c-0.6,0-1-0.4-1-1s0.4-1,1-1h18c0.6,0,1,0.4,1,1S21.6,15,21,15z"></path><path d="M17,19H3c-0.6,0-1-0.4-1-1s0.4-1,1-1h14c0.6,0,1,0.4,1,1S17.6,19,17,19z"></path></svg><span class="menu-text" data-v-756dcc9b>Menu</span></button><div class="VPLocalNavOutlineDropdown" style="--vp-vh:0px;" data-v-756dcc9b data-v-c8c65e5a><button data-v-c8c65e5a>Return to top</button><!----></div></div><aside class="VPSidebar" data-v-6305e88a data-v-5081c0c7><div class="curtain" data-v-5081c0c7></div><nav class="nav" id="VPSidebarNav" aria-labelledby="sidebar-aria-label" tabindex="-1" data-v-5081c0c7><span class="visually-hidden" id="sidebar-aria-label" data-v-5081c0c7> Sidebar Navigation </span><!--[--><!--]--><!--[--><div class="group" data-v-5081c0c7><section class="VPSidebarItem level-0" data-v-5081c0c7 data-v-79816cba><div class="item" role="button" tabindex="0" data-v-79816cba><div class="indicator" data-v-79816cba></div><h2 class="text" data-v-79816cba>我的项目</h2><!----></div><div class="items" data-v-79816cba><!--[--><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/project/ClipboardManager/" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>超级剪贴板</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/project/Markdown/" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>超级Markdown</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/project/JSRunner/" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>超级JavaScript</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/project/SmartWordBreak/" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>超级分词</p><!--]--><!----></a><!----></div><!----></div><!--]--></div></section></div><div class="group" data-v-5081c0c7><section class="VPSidebarItem level-0 collapsible collapsed" data-v-5081c0c7 data-v-79816cba><div class="item" role="button" tabindex="0" data-v-79816cba><div class="indicator" data-v-79816cba></div><h2 class="text" data-v-79816cba>开源作品</h2><div class="caret" role="button" aria-label="toggle section" tabindex="0" data-v-79816cba><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="caret-icon" data-v-79816cba><path d="M9,19c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l5.3-5.3L8.3,6.7c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l6,6c0.4,0.4,0.4,1,0,1.4l-6,6C9.5,18.9,9.3,19,9,19z"></path></svg></div></div><div class="items" data-v-79816cba><!--[--><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/works/opensource.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>个人作品</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/works/contribution.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>社区贡献</p><!--]--><!----></a><!----></div><!----></div><!--]--></div></section></div><div class="group" data-v-5081c0c7><section class="VPSidebarItem level-0 collapsible collapsed" data-v-5081c0c7 data-v-79816cba><div class="item" role="button" tabindex="0" data-v-79816cba><div class="indicator" data-v-79816cba></div><h2 class="text" data-v-79816cba>文章归档</h2><div class="caret" role="button" aria-label="toggle section" tabindex="0" data-v-79816cba><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="caret-icon" data-v-79816cba><path d="M9,19c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l5.3-5.3L8.3,6.7c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l6,6c0.4,0.4,0.4,1,0,1.4l-6,6C9.5,18.9,9.3,19,9,19z"></path></svg></div></div><div class="items" data-v-79816cba><!--[--><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E3%80%902023%E3%80%91%E9%9D%92%E8%AE%AD%E8%90%A5%20-%20%E5%89%8D%E7%AB%AF%E7%BB%83%E4%B9%A0%E9%A2%98%E6%B1%87%E6%80%BB%E8%A7%A3%E6%9E%90.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>【2023】青训营 - 前端练习题汇总解析</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E3%80%90%E5%AD%97%E8%8A%82%E8%B7%B3%E5%8A%A8%E3%80%91%E5%89%8D%E7%AB%AF%E9%9D%A2%E8%AF%95%E9%A2%98%E6%80%BB%E7%BB%93.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>【字节跳动】前端面试题总结</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E3%80%90%E5%BF%AB%E6%89%8B%E3%80%91%E6%B7%B1%E5%85%A5%E7%90%86%E8%A7%A3%E5%89%8D%E7%AB%AF%E9%9D%A2%E8%AF%95%E9%A2%98.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>【快手】深入理解前端面试题</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E3%80%90%E7%94%A8%E5%8F%8B%E9%87%91%E8%9E%8D%E3%80%91%E5%89%8D%E7%AB%AF%E9%9D%A2%E8%AF%95%E9%A2%98%E6%80%BB%E7%BB%93.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>【用友金融】前端面试题总结</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E4%B8%80%E6%96%87%E8%AF%BB%E6%87%82%E4%BA%8B%E4%BB%B6%E5%86%92%E6%B3%A1%E4%B8%8E%E4%BA%8B%E4%BB%B6%E6%8D%95%E8%8E%B7.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>一文读懂事件冒泡与事件捕获</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E4%B8%80%E6%96%87%E8%AF%BB%E6%87%82%E4%BC%AA%E7%B1%BB%E4%B8%8E%E4%BC%AA%E5%85%83%E7%B4%A0.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>一文读懂伪类与伪元素</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E4%B8%80%E6%96%87%E8%AF%BB%E6%87%82%E5%87%BD%E6%95%B0%E4%B8%ADthis%E6%8C%87%E5%90%91%E9%97%AE%E9%A2%98.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>一文读懂函数中this指向问题</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E4%BB%8E0%E5%AE%9E%E7%8E%B0%E4%B8%80%E4%B8%AA%E5%B9%B4%E5%BA%A6%E6%8A%A5%E5%91%8A.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>从0实现一个年度报告</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E5%BD%BB%E5%BA%95%E6%90%9E%E6%87%82%E5%AF%B9%E8%B1%A1%E7%9A%84%E6%95%B0%E6%8D%AE%E5%B1%9E%E6%80%A7%E6%8F%8F%E8%BF%B0%E7%AC%A6%E3%80%81%E5%AD%98%E5%82%A8%E5%B1%9E%E6%80%A7%E6%8F%8F%E8%BF%B0%E7%AC%A6.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>彻底搞懂对象的数据属性描述符、存储属性描述符</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E6%B5%85%E6%9E%90defineProperty%E4%B8%8EProxy%E5%AE%9E%E7%8E%B0%E7%9A%84%E5%8F%8C%E5%90%91%E7%BB%91%E5%AE%9A.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>浅析defineProperty与Proxy实现的双向绑定</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E6%B7%B1%E5%85%A5JavaScript%E6%95%B0%E6%8D%AE%E7%B1%BB%E5%9E%8B.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>深入JavaScript数据类型</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E6%B7%B1%E5%85%A5Vue3%E6%BA%90%E7%A0%81%EF%BC%8C%E7%9C%8B%E7%9C%8BVue.use%E5%90%8E%E7%A9%B6%E7%AB%9F%E5%8F%91%E7%94%9F%E4%BA%86%E4%BB%80%E4%B9%88%EF%BC%9F.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>深入Vue3源码，看看Vue.use后究竟发生了什么？</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E6%B7%B1%E5%85%A5%E7%90%86%E8%A7%A3Proxy%E4%B8%8EReflect.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>深入理解Proxy与Reflect</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E6%B7%B1%E5%85%A5%E7%90%86%E8%A7%A3%E6%B5%8F%E8%A7%88%E5%99%A8%E7%BC%93%E5%AD%98%E6%9C%BA%E5%88%B6.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>深入理解浏览器缓存机制</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/article/%E6%B7%B1%E5%85%A5%E7%90%86%E8%A7%A3%E6%B5%8F%E8%A7%88%E5%99%A8%E8%BF%90%E8%A1%8C%E5%8E%9F%E7%90%86.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>深入理解浏览器运行原理</p><!--]--><!----></a><!----></div><!----></div><!--]--></div></section></div><div class="group" data-v-5081c0c7><section class="VPSidebarItem level-0 collapsible has-active" data-v-5081c0c7 data-v-79816cba><div class="item" role="button" tabindex="0" data-v-79816cba><div class="indicator" data-v-79816cba></div><h2 class="text" data-v-79816cba>学习笔记</h2><div class="caret" role="button" aria-label="toggle section" tabindex="0" data-v-79816cba><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" viewbox="0 0 24 24" class="caret-icon" data-v-79816cba><path d="M9,19c-0.3,0-0.5-0.1-0.7-0.3c-0.4-0.4-0.4-1,0-1.4l5.3-5.3L8.3,6.7c-0.4-0.4-0.4-1,0-1.4s1-0.4,1.4,0l6,6c0.4,0.4,0.4,1,0,1.4l-6,6C9.5,18.9,9.3,19,9,19z"></path></svg></div></div><div class="items" data-v-79816cba><!--[--><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/JavaScript.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>JavaScript基础</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/CSS.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>CSS基础</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/JavaScriptEnhanced.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>JavaScript进阶</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/Front-end%20Engineering.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>前端工程化</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/SSR.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>服务端渲染</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/React.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>React基础</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/React%20Hooks.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>React Hooks</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link is-active has-active" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/Redux.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>Redux</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/React%20Router.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>React Router</p><!--]--><!----></a><!----></div><!----></div><div class="VPSidebarItem level-1 is-link" data-v-79816cba data-v-79816cba><div class="item" data-v-79816cba><div class="indicator" data-v-79816cba></div><a class="VPLink link link" href="/note/MySQL.html" data-v-79816cba data-v-fd6e3585><!--[--><p class="text" data-v-79816cba>MySQL</p><!--]--><!----></a><!----></div><!----></div><!--]--></div></section></div><!--]--><!--[--><!--]--></nav></aside><div class="VPContent has-sidebar" id="VPContent" data-v-6305e88a data-v-435404df><div class="VPDoc has-sidebar has-aside" data-v-435404df data-v-25140dfd><!--[--><!--]--><div class="container" data-v-25140dfd><div class="aside" data-v-25140dfd><div class="aside-curtain" data-v-25140dfd></div><div class="aside-container" data-v-25140dfd><div class="aside-content" data-v-25140dfd><div class="VPDocAside" data-v-25140dfd data-v-2b53d15f><!--[--><!--]--><!--[--><!--]--><div class="VPDocAsideOutline" data-v-2b53d15f data-v-1cf492a7><div class="content" data-v-1cf492a7><div class="outline-marker" data-v-1cf492a7></div><div class="outline-title" data-v-1cf492a7>On this page</div><nav aria-labelledby="doc-outline-aria-label" data-v-1cf492a7><span class="visually-hidden" id="doc-outline-aria-label" data-v-1cf492a7> Table of Contents for current page </span><ul class="root" data-v-1cf492a7 data-v-e09875d9><!--[--><!--]--></ul></nav></div></div><!--[--><!--]--><div class="spacer" data-v-2b53d15f></div><!--[--><!--]--><!----><!--[--><!--]--><!--[--><!--]--></div></div></div></div><div class="content" data-v-25140dfd><div class="content-container" data-v-25140dfd><!--[--><!--]--><!----><main class="main" data-v-25140dfd><div style="position:relative;" class="vp-doc _note_Redux" data-v-25140dfd><div><h1 id="redux" tabindex="-1">Redux <a class="header-anchor" href="#redux" aria-label="Permalink to &quot;Redux&quot;">​</a></h1><h2 id="理解javascript的纯函数" tabindex="-1">理解JavaScript的纯函数 <a class="header-anchor" href="#理解javascript的纯函数" aria-label="Permalink to &quot;理解JavaScript的纯函数&quot;">​</a></h2><ul><li>函数式编程中有一个非常重要的概念 <strong>纯函数</strong>，JavaScript符合函数式编程的范式，所以也有纯函数的概念 <ul><li>在React开发中，纯函数被多次提及：</li><li>React组件被要求像一个纯函数（为什么是像，因为还有类组件）</li><li>Redux中有一个reducer的概念，同样是要求必须是一个纯函数</li></ul></li><li>掌握纯函数对于理解很多框架的设计都是有帮助的</li></ul><p>一个纯函数必然具备以下特征：</p><ul><li>确定的输入一定产生确定的输出</li><li>函数的执行过程中，不能产生副作用</li></ul><h2 id="为什么需要redux" tabindex="-1">为什么需要Redux <a class="header-anchor" href="#为什么需要redux" aria-label="Permalink to &quot;为什么需要Redux&quot;">​</a></h2><ul><li>JS需要管理的状态越来越多，越来越复杂</li><li>状态不断发生变化之间又相互依赖，这要求视图层也能同步更新</li><li>React提供了自动更新视图的方法，但状态仍需要手动管理</li><li>Redux可以帮我们管理状态，提供了<strong>可预测的状态管理</strong></li><li>框架无关，体积只有2KB大小</li></ul><h2 id="redux的核心理念" tabindex="-1">Redux的核心理念 <a class="header-anchor" href="#redux的核心理念" aria-label="Permalink to &quot;Redux的核心理念&quot;">​</a></h2><p>Redux的核心理念 Store</p><ul><li>定义一个统一的规范来操作数据，这样就可以做到对数据的跟踪</li><li><code>list.push()</code> <code>list[0].age = 18</code></li></ul><p>Redux的核心理念 Action</p><ul><li>Redux要求：要修改数据，必须通过Action来修改</li><li>所有数据的变化，必须通过派发（Patch）Action来更新</li><li>Action是一个普通的JS对象，用来描述此次更新的type与content</li><li><code>const action = { type: &#39;ADD_ITEM&#39;, item: { name: &#39;Ziu&#39;, age: 18 } }</code></li></ul><p>Redux的核心理念 Reducer</p><ul><li>如何将Store和Action联系在一起？</li><li>reducer是一个纯函数</li><li>完成的工作就是：将传入的state和action结合起来，生成一个新的state</li><li><code>patch</code> =&gt; <code>reducer</code> =&gt; <code>newState</code> =&gt; <code>Store</code></li></ul><h2 id="redux-demo" tabindex="-1">Redux Demo <a class="header-anchor" href="#redux-demo" aria-label="Permalink to &quot;Redux Demo&quot;">​</a></h2><p>下例中，通过<code>createStore</code>创建了一个Store（已经不推荐了）</p><ul><li>initialState用于在调用<code>createStore</code>时作为默认值传入<code>reducer</code></li><li>后续每次<code>store.dispatch</code>都会调用<code>reducer</code></li><li>通过<code>reducer</code>更新state中的数据</li></ul><p>在React中，可以通过<code>store.subscribe</code>注册State变化的监听回调</p><ul><li>当state发生变化时，通过调用<code>this.forceUpdate</code>触发组件的更新</li><li>一般情况下，我们在<code>componentDidMount</code>注册监听回调，在<code>componentWillUnmount</code>解除监听</li></ul><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-Lh8Im" id="tab-zlIuWkT" checked="checked"><label for="tab-zlIuWkT">App.jsx</label><input type="radio" name="group-Lh8Im" id="tab-23h-dpZ"><label for="tab-23h-dpZ">index.js</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// App.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">App</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">componentDidMount</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;"> </span><span style="color:#676E95;font-style:italic;">// Subscribe to the store</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">subscribe</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">subscribe</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#82AAFF;">forceUpdate</span><span style="color:#F07178;">()</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">componentWillUnmount</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">unsubscribe</span><span style="color:#F07178;">()</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h1</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">App</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h1</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Count: </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Name: </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">name</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">INCREMENT</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;"> +1 </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">DECREMENT</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;"> -1 </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">CHANGE_NAME</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">name</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">ZIU</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">}&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> CHANGE_NAME</span><span style="color:#89DDFF;">{</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createStore</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// The initial application state</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// This is the same as the state argument we passed to the createStore function</span></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> initialState </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">count</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">name</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">Ziu</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// Reducer: a pure function that takes the previous state and an action, and returns the next state.</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// (previousState, action) =&gt; newState</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">reducer</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> initialState</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">reducer</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">switch</span><span style="color:#F07178;"> (</span><span style="color:#A6ACCD;">action</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">type</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">case</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">INCREMENT</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#89DDFF;"> </span><span style="color:#676E95;font-style:italic;">// NOTE: Keep functions pure - do not mutate the original state.</span></span>
<span class="line"><span style="color:#89DDFF;"> </span><span style="color:#676E95;font-style:italic;">// Desctructure the state object and return a **new object** with the updated count</span></span>
<span class="line"><span style="color:#89DDFF;"> </span><span style="color:#676E95;font-style:italic;">// Instead of `return state.count++`</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> count</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#F78C6C;">1</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">case</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">DECREMENT</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> count</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">-</span><span style="color:#F07178;"> </span><span style="color:#F78C6C;">1</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">case</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">CHANGE_NAME</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> name</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">name</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createStore</span><span style="color:#A6ACCD;">(reducer)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> store</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br><span class="line-number">36</span><br><span class="line-number">37</span><br><span class="line-number">38</span><br><span class="line-number">39</span><br><span class="line-number">40</span><br><span class="line-number">41</span><br><span class="line-number">42</span><br></div></div></div></div><p><img src="/assets/redux-usage.7df84df8.svg" alt="redux-usage"></p><h2 id="进一步封装" tabindex="-1">进一步封装 <a class="header-anchor" href="#进一步封装" aria-label="Permalink to &quot;进一步封装&quot;">​</a></h2><p>可以将耦合在一起的代码拆分到不同文件中</p><ul><li>将<code>reducer</code>抽取出来<code>reducer.js</code>，简化<code>store/index.js</code>内容</li><li>将<code>action.type</code>抽取为常量<code>constants.js</code>，使用时做导入，以保证一致性</li><li>将<code>action</code>抽取出来<code>actionFactory.js</code>，用于外部dispatch时规范类型</li></ul><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-md8PE" id="tab-DC1dYx9" checked="checked"><label for="tab-DC1dYx9">index.js</label><input type="radio" name="group-md8PE" id="tab-__C3jbo"><label for="tab-__C3jbo">constants.js</label><input type="radio" name="group-md8PE" id="tab-kijLFgH"><label for="tab-kijLFgH">reducer.js</label><input type="radio" name="group-md8PE" id="tab-qIcdZFW"><label for="tab-qIcdZFW">actionFactory.js</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createStore</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> reducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./reducer</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createStore</span><span style="color:#A6ACCD;">(reducer)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> store</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// constants.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> INCREMENT </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">INCREMENT</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> DECREMENT </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">DECREMENT</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> CHANGE_NAME </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">CHANGE_NAME</span><span style="color:#89DDFF;">&#39;</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// reducer.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">*</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">as</span><span style="color:#A6ACCD;"> actionType </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./constants</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> initialState </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">count</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#F78C6C;">0</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">name</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">Ziu</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">reducer</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> initialState</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">switch</span><span style="color:#F07178;"> (</span><span style="color:#A6ACCD;">action</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">type</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">case</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">INCREMENT</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> count</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#F78C6C;">1</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">case</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">DECREMENT</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> count</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">-</span><span style="color:#F07178;"> </span><span style="color:#F78C6C;">1</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">case</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">CHANGE_NAME</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> name</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">name</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#89DDFF;">:</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// actionFactory.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">*</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">as</span><span style="color:#A6ACCD;"> actionType </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./constants</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> increment </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">INCREMENT</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> decrement </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">DECREMENT</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> changeName </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">name</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">CHANGE_NAME</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> name</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// App.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">increment</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">decrement</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">changeName</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store/actionFactory</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">App</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">componentDidMount</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">subscribe</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#82AAFF;">forceUpdate</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">componentWillUnmount</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">unsubscribe</span><span style="color:#F07178;">()</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h1</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">App</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h1</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Count: </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Name: </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">name</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">increment</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;"> +1 </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">decrement</span><span style="color:#A6ACCD;">())</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;"> -1 </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">changeName</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">ZIU</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">))</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;">CHANGE_NAME</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br></div></div><h2 id="redux的三大原则" tabindex="-1">Redux的三大原则 <a class="header-anchor" href="#redux的三大原则" aria-label="Permalink to &quot;Redux的三大原则&quot;">​</a></h2><p>单一数据源</p><ul><li>整个应用程序的状态都被存储在一棵Object Tree上</li><li>且这个Object Tree只存储在一个Store中</li><li>但Redux并不强制限制创建多Store，不利于数据维护</li><li>单一数据源有利于整个应用程序的维护、追踪、修改</li></ul><p>State属性是只读的</p><ul><li>允许修改State的方法只有patch action，不要直接修改State</li><li>确保了View或网络请求都不能修改State</li><li>保证所有的修改都能被追踪、按照严格的顺序执行，不用担心竞态（race condition）的问题</li></ul><p>使用纯函数来执行修改</p><ul><li>通过reducer将旧State与新State联系在一起，并且返回一个<strong>新的State</strong></li><li>随着应用程序复杂程度增加，可以将reducer拆分为多个小的reducer，分别用于操作不同State Tree的某一部分</li><li>所有的reducer都应该是纯函数，不能产生任何的副作用</li></ul><h2 id="优化重复代码" tabindex="-1">优化重复代码 <a class="header-anchor" href="#优化重复代码" aria-label="Permalink to &quot;优化重复代码&quot;">​</a></h2><p>当编写了一些案例的时候会发现，React结合Redux时会编写很多重复的代码</p><p>在每个需要用到Redux中状态的组件中，都需要在不同生命周期做添加订阅/解除订阅的处理，组件初始化时还要从store中取最新的状态</p><p>针对重复代码的问题，可以使用之前学到的高阶组件来做优化</p><p>Redux官方提供的库<code>react-redux</code>，可以让我们更方便的在React中使用Redux</p><div class="language-bash line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">bash</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#FFCB6B;">npm</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">i</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">react-redux</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><p>在Profile组件中，通过高阶函数<code>connect</code>实现的</p><p>将store中需要的状态通过<code>mapStoreToProps</code>转为props，并将需要使用store中状态的组件传入调用connect返回的函数中</p><p>在<code>Profile</code>组件中就可以从props中获取到store中的状态</p><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-NbpDf" id="tab-WUpjB4O" checked="checked"><label for="tab-WUpjB4O">App.jsx</label><input type="radio" name="group-NbpDf" id="tab-0Ut4R5H"><label for="tab-0Ut4R5H">Profile.jsx</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// App.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Provider</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react-redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> Profile </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./Profile</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">App</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">Provider</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">store</span><span style="color:#89DDFF;">={</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">}&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">App</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">Profile</span><span style="color:#89DDFF;">&gt;&lt;/</span><span style="color:#FFCB6B;">Profile</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#FFCB6B;">Provider</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// Profile.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Component</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">connect</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react-redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// mapStateToProps is a function that</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// takes the state of the store as an argument</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// and returns an object with the data that the component needs from the store.</span></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// component will receive the data as props.</span></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapStateToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">count</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#A6ACCD;">(mapStateToProps)(</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Profile</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Component</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Profile</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Count: </span><span style="color:#89DDFF;">{this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br></div></div></div></div><p>我们刚刚只是完成了对State的映射，将Store中保存的全局状态state映射到了Profile组件的props中</p><p>connect还可以传入第二个参数，用于将action也映射到props中：</p><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// Profile.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Component</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">connect</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react-redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line highlighted"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">INCREMENT</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">DECREMENT</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store/constants</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapStateToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">count</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line highlighted"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapDispatchToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">dispatch</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">increment</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> INCREMENT </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">,</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">decrement</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">type</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> DECREMENT </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line highlighted"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#A6ACCD;">(</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapStateToProps</span><span style="color:#89DDFF;">,</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> mapDispatchToProps</span></span>
<span class="line"><span style="color:#A6ACCD;">)(</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Profile</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Component</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Profile</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Count: </span><span style="color:#89DDFF;">{this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">p</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">increment</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;"> +1 </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">decrement</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;"> -1 </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br></div></div><p>本质上是<code>connect</code>内部对操作进行了封装，把逻辑隐藏起来了：</p><ul><li>调用<code>connect</code>这个<strong>高阶函数</strong>，返回一个<strong>高阶组件</strong></li><li>为高阶组件传入映射目标组件，最后高阶组件返回一个新组件</li><li>新组件的props包含了来自Store中状态/dispatch的映射</li></ul><h2 id="异步action" tabindex="-1">异步Action <a class="header-anchor" href="#异步action" aria-label="Permalink to &quot;异步Action&quot;">​</a></h2><p>有些场景下，我们希望组件能够直接调用Store中的action来触发网络请求，并且获取到数据</p><p>但是dispatch只允许派发对象类型的Action，不能通过dispatch派发函数</p><p>可以通过中间件<code>redux-thunk</code>来对Redux做增强，让dispatch能够对函数进行派发</p><div class="language-bash line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">bash</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#FFCB6B;">npm</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">i</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">redux-thunk</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><p>通过<code>applyMiddleware</code>引入<code>redux-thunk</code>这个中间件：</p><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-8E3Vh" id="tab-dvQomQq" checked="checked"><label for="tab-dvQomQq">index.js</label><input type="radio" name="group-8E3Vh" id="tab-kSx1n30"><label for="tab-kSx1n30">actionFactory.js</label><input type="radio" name="group-8E3Vh" id="tab-TVwzhvk"><label for="tab-TVwzhvk">list.jsx</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line highlighted"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createStore</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">applyMiddleware</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line highlighted"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> thunk </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">redux-thunk</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> reducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./reducer</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line highlighted"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createStore</span><span style="color:#A6ACCD;">(reducer</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">applyMiddleware</span><span style="color:#A6ACCD;">(thunk))</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> store</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// actionFactory.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fetchPostList </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">dispatch</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;font-style:italic;">getState</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#82AAFF;">fetch</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">https://jsonplaceholder.typicode.com/posts</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">then</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">res</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">res</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">json</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">then</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">res</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> type</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">actionType</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">FETCH_POST_LIST</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> list</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">res</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// list.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Component</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">connect</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react-redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store/actionFactory</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapStateToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">list</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">list</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapDispatchToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">dispatch</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">fetchList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">fetchPostList</span><span style="color:#A6ACCD;">())</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#A6ACCD;">(</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapStateToProps</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapDispatchToProps</span></span>
<span class="line"><span style="color:#A6ACCD;">)(</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Profile</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Component</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">List</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">fetchList</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;">Fetch List</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">list</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">length </span><span style="color:#89DDFF;">&amp;&amp;</span><span style="color:#A6ACCD;"> (</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">ul</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">list</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">map</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">item</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">li</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">key</span><span style="color:#89DDFF;">={</span><span style="color:#A6ACCD;">item</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">id</span><span style="color:#89DDFF;">}&gt;{</span><span style="color:#A6ACCD;">item</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">title</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">li</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> ))</span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">ul</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> )</span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br></div></div></div></div><ul><li>这样就可以将网络请求的具体逻辑代码隐藏到Redux中</li><li>将网络请求归于状态管理的一部分</li><li>而不是书写在组件内，不利于维护，耦合度太高</li></ul><p><code>redux-thunk</code>是如何做到可以让我们发送异步请求的？</p><ul><li>默认情况下<code>dispatch(action)</code>的action必须为一个JS对象</li><li><code>redux-thunk</code>允许我们传入一个函数作为<code>action</code></li><li>函数会被调用，并且将<code>dispatch</code>函数和<code>getState</code>函数作为入参传递给这个函数action <ul><li><code>dispatch</code> 允许我们在这之后再次派发<code>action</code></li><li><code>getState</code> 允许我们之后的一些操作依赖原来的状态，可以获取到之前的状态</li></ul></li></ul><p>下图展示了从组件调用方法，触发patch到Redux接收patch、发送网络请求、更新state的全过程：</p><p><img src="/assets/redux-async-action.0dc40e11.svg" alt="redux-async-action"></p><h2 id="拆分store" tabindex="-1">拆分Store <a class="header-anchor" href="#拆分store" aria-label="Permalink to &quot;拆分Store&quot;">​</a></h2><p>拆分Store带来的益处很多，便于多人协作、不同业务逻辑解耦等</p><p>在Redux中，拆分Store的本质是拆分不同的<code>reducer</code>函数，之前在使用<code>createStore</code>时，传入的就是<code>reducer</code>函数</p><p>之前的Store写法与用法：</p><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createStore</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> reducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./reducer</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createStore</span><span style="color:#A6ACCD;">(reducer)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// App.jsx</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">list</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br></div></div><p>拆分Store后的写法与用法：</p><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createStore</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">combineReducers</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> counterReducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./counter</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> postListReducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./postList</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> reducer </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">combineReducers</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">counter</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> counterReducer</span><span style="color:#89DDFF;">,</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">postList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> postListReducer</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createStore</span><span style="color:#A6ACCD;">(reducer)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// App.jsx</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">counter</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><p>拆分为多个Reducer之后，需要首先<code>getState()</code>获取到整个状态树，随后指定获取到不同的模块中的状态</p><p>拆分后，不同模块下的文件是保持一致的：</p><div class="language-sh line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">sh</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">store/</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;"># Store根目录</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">index.js</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;"># 导出 store 位置</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">counter/</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;"># Counter模块</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">actionFactory.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">constants.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">index.js</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;"># 统一导出</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">reducer.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">postList/</span><span style="color:#A6ACCD;"> </span><span style="color:#676E95;font-style:italic;"># PostList模块</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">actionFactory.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">constants.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">index.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">reducer.js</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">-</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">...</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><h3 id="combinereducer函数" tabindex="-1">combineReducer函数 <a class="header-anchor" href="#combinereducer函数" aria-label="Permalink to &quot;combineReducer函数&quot;">​</a></h3><p>前面拆分Store时用到了<code>combineReducer</code>函数，将多个模块reducer组合到一起，函数内部是如何处理的？</p><ul><li>将传入的reducers合并到一个对象中，最终返回一个<code>combination</code>函数（相当于未拆分时传给<code>createStore</code>的<code>reducer</code>函数）</li><li>在执行<code>combination</code>函数的过程中，它会通过判断前后返回的数据是否相同来决定返回之前的state还是新的state</li><li>新state会触发订阅者发生对应更新，而旧state可以有效地组织订阅者发生刷新</li></ul><p>下面简单写了一下<code>combineReducer</code>的实现原理</p><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// 使用</span></span>
<span class="line"><span style="color:#82AAFF;">combineReducer</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">counter</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> combineReducer</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">postList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> postListReducer</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#676E95;font-style:italic;">// 创建一个新的reducer</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">reducer</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{},</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;"> </span><span style="color:#676E95;font-style:italic;">// 返回一个对象 是Store的state</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> counter</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">counterReducer</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">counter</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#F07178;"> postList</span><span style="color:#89DDFF;">:</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">postListReducer</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><h2 id="reduxtoolkit" tabindex="-1">ReduxToolkit <a class="header-anchor" href="#reduxtoolkit" aria-label="Permalink to &quot;ReduxToolkit&quot;">​</a></h2><ul><li>ReduxToolkit重构</li><li>ReduxToolkit异步</li><li>connect高阶组件</li><li>中间件的实现原理</li><li>React状态管理选择</li></ul><h2 id="认识reduxtoolkit" tabindex="-1">认识ReduxToolkit <a class="header-anchor" href="#认识reduxtoolkit" aria-label="Permalink to &quot;认识ReduxToolkit&quot;">​</a></h2><p>之前在使用<code>createStore</code>创建Store时会出现deprecated标识，推荐我们使用<code>@reduxjs/toolkit</code>包中的<code>configureStore</code>函数</p><p>Redux Toolkit是官方推荐编写Redux逻辑的方法</p><ul><li>在前面学习Redux时已经发现，Redux的逻辑编写过于繁琐、麻烦</li><li>代码分拆在不同模块中，存在大量重复代码</li><li>Redux Toolkit旨在成为编写Redux逻辑的标准方式，从而解决上面提到的问题</li><li>这个包常被称为：RTK</li></ul><h2 id="使用reduxtoolkit重写store" tabindex="-1">使用ReduxToolkit重写Store <a class="header-anchor" href="#使用reduxtoolkit重写store" aria-label="Permalink to &quot;使用ReduxToolkit重写Store&quot;">​</a></h2><p>Redux Toolkit依赖于react-redux包，所以需要同时安装这二者</p><div class="language-bash line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">bash</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#FFCB6B;">npm</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">i</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">@reduxjs/toolkit</span><span style="color:#A6ACCD;"> </span><span style="color:#C3E88D;">react-redux</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><p>Redux Toolkit的核心API主要是下述几个：</p><ul><li><code>configureStore</code> 包装createStore以提供简化的配置选项和良好的默认值 <ul><li>可以自动组合你的slice reducer 添加你提供的任何Redux中间件</li><li>默认包含redux-thunk，并启用Redux DevTools Extension</li></ul></li><li><code>createSlice</code> 创建切片 片段 <ul><li>接受reducer函数的对象、切片名称和初始状态值，并自动生成切片reducer，并带有actions</li></ul></li><li><code>createAsyncThunk</code><ul><li>接受一个动作类型字符串和一个返回Promise的函数</li><li>并生成一个<code>pending / fullfilled / rejected</code>基于该承诺分派动作类型的thunk</li></ul></li></ul><p>写一个Demo：</p><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-WtJer" id="tab-SeKqP72" checked="checked"><label for="tab-SeKqP72">index.js</label><input type="radio" name="group-WtJer" id="tab--3TQBTt"><label for="tab--3TQBTt">counter.js</label><input type="radio" name="group-WtJer" id="tab-EuJ2mnv"><label for="tab-EuJ2mnv">Counter.jsx</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">configureStore</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">@reduxjs/toolkit</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> counterSlice </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./features/counter</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">configureStore</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">reducer</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">counter</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> counterSlice</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> store</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/features/counter.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createSlice</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">@reduxjs/toolkit</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> counterSlice </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createSlice</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">name</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">counter</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">initialState</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">count</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#F78C6C;">0</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">reducers</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">addCount</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">subCount</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">-=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> actions</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> reducer </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> counterSlice</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> addCount</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> subCount </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> actions</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> reducer</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// Counter.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Component</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">connect</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react-redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">addCount</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">subCount</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../store/features/counter</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapStateToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">count</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">counter</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">count</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapDispatchToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">dispatch</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">increment</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">count</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">addCount</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">decrement</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">count</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">subCount</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#A6ACCD;">(</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapStateToProps</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapDispatchToProps</span></span>
<span class="line"><span style="color:#A6ACCD;">)(</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Counter</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Component</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">count</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">props</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">Counter</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h2</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">count: </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;">count</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">increment</span><span style="color:#A6ACCD;">(</span><span style="color:#F78C6C;">1</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;">+1</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">decrement</span><span style="color:#A6ACCD;">(</span><span style="color:#F78C6C;">1</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;">-1</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br><span class="line-number">36</span><br><span class="line-number">37</span><br><span class="line-number">38</span><br><span class="line-number">39</span><br></div></div></div></div><p><code>createSlice</code> 函数参数解读</p><ul><li><code>name</code> 标记Slice 展示在dev-tool中</li><li><code>initialState</code> 初始化状态</li><li><code>reducers</code> 对象 对应之前的reducer函数</li><li>返回值: 一个对象 包含所有actions</li></ul><p><code>configureStore</code> 解读</p><ul><li><code>reducer</code> 将slice中的reducer组成一个对象，传入此参数</li><li><code>middleware</code> 额外的中间件 <ul><li>RTK已经为我们集成了<code>redux-thunk</code>和<code>redux-devtool</code>两个中间件</li></ul></li><li><code>devTools</code> 布尔值 是否启用开发者工具</li></ul><h2 id="使用rtk执行异步dispatch" tabindex="-1">使用RTK执行异步dispatch <a class="header-anchor" href="#使用rtk执行异步dispatch" aria-label="Permalink to &quot;使用RTK执行异步dispatch&quot;">​</a></h2><p>实际场景中都是在组件中发起网络请求，并且将状态更新到Store中</p><p>之前的开发中，我们通过<code>redux-thunk</code>这个中间件，让dispatch中可以进行异步操作</p><p>ReduxToolkit默认已经给我们集成了Thunk相关的功能：<code>createAsyncThunk</code></p><p>下面我们使用RTK实现一下这个场景：在Profile中请求postList数据并保存在Store中，并展示出来</p><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-eHYQj" id="tab-jRtjHDM" checked="checked"><label for="tab-jRtjHDM">postList.js</label><input type="radio" name="group-eHYQj" id="tab-3bcfKIr"><label for="tab-3bcfKIr">index.js</label><input type="radio" name="group-eHYQj" id="tab-OpT6Gp-"><label for="tab-OpT6Gp-">Profile.jsx</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/features/postList.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createSlice</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createAsyncThunk</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">@reduxjs/toolkit</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line highlighted"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fetchPostList </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createAsyncThunk</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fetch/postList</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">async</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">url</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">https://jsonplaceholder.typicode.com/posts</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">data</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">fetch</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">url</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">then</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">res</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">res</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">json</span><span style="color:#F07178;">())</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">data</span></span>
<span class="line highlighted"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> postListSlice </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createSlice</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">name</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">postList</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">initialState</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">postList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> []</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">reducers</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">setPostList</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">})</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">extraReducers</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">[</span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">fulfilled</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">})</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">payload</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">[</span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">pending</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">})</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fetchPostList.pending</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">[</span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">rejected</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">})</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fetchPostList.rejected</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> setPostList </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> postListSlice</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">actions</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> postListSlice</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">reducer</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br><span class="line-number">36</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// store/index.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">configureStore</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">@reduxjs/toolkit</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> counterReducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./features/counter</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> postListReducer </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./features/postList</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">configureStore</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">reducer</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">counter</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> counterReducer</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">postList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> postListReducer</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// Profile.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Component</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">connect</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react-redux</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../store/features/postList</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapStateToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">postList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> mapDispatchToProps </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">dispatch</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">fetchPostList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">fetchPostList</span><span style="color:#A6ACCD;">())</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#A6ACCD;">(</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapStateToProps</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> mapDispatchToProps</span></span>
<span class="line"><span style="color:#A6ACCD;">)(</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Profile</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Component</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> Profile</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">onClick</span><span style="color:#89DDFF;">={()</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">fetchPostList</span><span style="color:#A6ACCD;">()</span><span style="color:#89DDFF;">}&gt;</span><span style="color:#A6ACCD;">Fetch Data</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">button</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">ul</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">map</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">item</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">index</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> (</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">li</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">key</span><span style="color:#89DDFF;">={</span><span style="color:#A6ACCD;">index</span><span style="color:#89DDFF;">}&gt;{</span><span style="color:#A6ACCD;">item</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">title</span><span style="color:#89DDFF;">}&lt;/</span><span style="color:#F07178;">li</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> ))</span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">ul</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">)</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br></div></div></div></div><p>当<code>createAsyncThunk</code>创建出来的action被dispatch时，会存在三种状态：</p><ul><li>pending: action被发出，但是还没有最终的结果</li><li>fulfilled: 获取到最终的结果（有返回值的结果）</li><li>rejected: 执行过程中又错误或者抛出了异常</li></ul><p>我们可以在<code>createSlice</code>的<code>entraReducer</code>中监听这些结果，根据派发action后的状态添加不同的逻辑进行处理</p><p>除了上述的写法，还可以为<code>extraReducer</code>传入一个函数，函数接收一个<code>builder</code>作为参数，在函数体内添加不同的case来监听异步操作的结果：</p><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// postList.js</span></span>
<span class="line"><span style="color:#89DDFF;">...</span></span>
<span class="line"><span style="color:#FFCB6B;">extraReducers</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">builder</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">builder</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">addCase</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">fulfilled</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">})</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">builder</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">addCase</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">pending</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">})</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fetchPostList.pending</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">builder</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">addCase</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">fetchPostList</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">rejected</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">})</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fetchPostList.rejected</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">...</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><p>在之前的代码中，我们都是通过触发action后置的回调来更新state，那么有没有可能在请求完毕时确定性地更新store中的state？</p><p>可以当请求有结果了，在请求成功的回调中直接dispatch设置state的action</p><p>当我们通过dispatch触发异步action时可以传递额外的参数，这些参数可以在传入createAsyncThunk的回调函数的参数中获取到，同时也可以从函数的参数中获取到<code>dispatch</code>与<code>getState</code>函数，这样就可以在请求到数据后直接通过派发action的方式更新store中的state，下面是修改后的例子：</p><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// postList.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createSlice</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createAsyncThunk</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">@reduxjs/toolkit</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> fetchPostList </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createAsyncThunk</span><span style="color:#A6ACCD;">(</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">fetch/postList</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span></span>
<span class="line highlighted"><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">async</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">extraInfo</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">dispatch</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">getState</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">})</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">url</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">https://jsonplaceholder.typicode.com/posts</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">data</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">await</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">fetch</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">url</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">then</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">res</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">res</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">json</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#82AAFF;">dispatch</span><span style="color:#F07178;">(</span><span style="color:#82AAFF;">setPostList</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">data</span><span style="color:#F07178;">))</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> postListSlice </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createSlice</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">name</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">postList</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">initialState</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">postList</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> []</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">reducers</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">setPostList</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">state</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">payload</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">})</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">postList</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">payload</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#A6ACCD;"> setPostList </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> postListSlice</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">actions</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> postListSlice</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">reducer</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br></div></div><p>当然，此时异步action的状态已经不那么重要了，也就不必再<code>return data</code>了，除非你需要对异常状态做额外处理，仍然可以在<code>extraReducers</code>中添加异常处理回调</p><h2 id="redux-toolkit的数据不可变性" tabindex="-1">Redux Toolkit的数据不可变性 <a class="header-anchor" href="#redux-toolkit的数据不可变性" aria-label="Permalink to &quot;Redux Toolkit的数据不可变性&quot;">​</a></h2><p>Redux Toolkit本质是对之前繁琐的操作进行的一次封装</p><p>我们注意到：在之前reducer对state进行更新时，必须返回一个新的state才能触发修改<code>state = { ...state, count: count + 1 }</code>，但是经过Redux Toolkit的封装，我们只需要<code>state.count += 1</code>，直接对状态进行赋值就可以完成状态的更新</p><p>这是因为在RTK内部使用了<code>immutable.js</code>，数据不可变性</p><ul><li>在React开发中，我们总是强调数据的不可变性 <ul><li>无论是类组件中的state还是redux中管理的state</li><li>JS的编码过程里，数据的不可变性都是非常重要的</li></ul></li><li>所以在之前我们更新state时都是通过浅拷贝来完成的 <ul><li>但是浅拷贝也存在它的缺陷：</li><li>当对象过大时，进行浅拷贝会造成性能的浪费</li><li>浅拷贝后的新对象，其深层属性仍然是旧对象的引用</li></ul></li></ul><p>Redux Toolkit底层使用了<code>immerjs</code>库来保证数据的不可变性</p><p>immutablejs库的底层原理和使用方法：<a href="https://mp.weixin.qq.com/s/hfeCDCcodBCGS5GpedxCGg" target="_blank" rel="noreferrer">React系列十八 - Redux(四)state如何管理</a></p><p>为了节约内存，出现了新的算法<code>Persistent Data Structure</code>持久化数据结构/一致性数据结构</p><ul><li>用一种数据结构来保存数据</li><li>当数据被修改时，会返回一个新的对象，但是新的对象会尽可能复用之前的数据结构而不会对内存进行浪费</li><li>比如有一棵引用层级较深的树，当我们对其深层某个节点进行修改时，不会完全拷贝整棵树，而是在尽可能复用旧树结构的同时创建一棵新的树</li></ul><p>一图胜千言：</p><p><img src="/assets/immutable.dc41f87b.gif" alt="immutable"></p><h2 id="connect的实现原理" tabindex="-1">connect的实现原理 <a class="header-anchor" href="#connect的实现原理" aria-label="Permalink to &quot;connect的实现原理&quot;">​</a></h2><p>connect函数是<code>react-redux</code>提供的一个高阶函数，它返回一个高阶组件，用于将store中的state/dispatch映射为组件的props</p><p>下面一步一步手写一个connect函数，实现和库提供的connect一样的映射功能：</p><p>首先完成基本的代码搭建，connect函数接收两个参数<code>mapStateToProps</code> <code>mapDispatchToProps</code>返回一个高阶组件</p><p>所谓高阶组件，就是传入一个类组件，返回一个增强后的新的类组件：</p><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// connect.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">mapStateToProps</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">mapDispatchToProps</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">WrapperComponent</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">class</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">InnerComponent</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">extends</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> render</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">WrapperComponent</span><span style="color:#89DDFF;"> {...this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">} /&gt;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br></div></div><p>其中，<code>mapStateToProps</code>和<code>mapDispatchToProps</code>都是函数，函数入参是<code>state</code>与<code>dispatch</code>，返回一个对象，键值对对应<code>prop &lt;=&gt; state/dispatch调用</code></p><p>我们导入store，并且从store中获取到state和dispatch传入<code>mapStateToProps</code>和<code>mapDispatchToProps</code>，随后将得到的键值对以props形式传递给WrapperComponent</p><p>这样新组件就可以拿到这些状态与dispatch方法，我们可以在<code>componentDidMount</code>中监听整个store，当store中的状态发生改变时，强制执行re-render</p><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// connect.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../store</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">mapStateToProps</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">mapDispatchToProps</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">WrapperComponent</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">class</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">InnerComponent</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">extends</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> componentDidMount</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">subscribe</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#82AAFF;">forceUpdate</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> render</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapDispatchToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">WrapperComponent</span><span style="color:#89DDFF;"> {...this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">} {...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">} {...</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#89DDFF;">} /&gt;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br></div></div><p>上述代码能够正常工作，但是显然每次store内state发生改变都re-render是不明智的，因为组件可能只用到了store中的某些状态</p><p>那些组件没有用到的其他状态发生改变时，组件不应该也跟着re-render，这里可以做一些优化</p><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// connect.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">../store</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">mapStateToProps</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">mapDispatchToProps</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">WrapperComponent</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">class</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">InnerComponent</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">extends</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">constructor</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">props</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">super</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">props</span><span style="color:#F07178;">)</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">state</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> componentDidMount</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">subscribe</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#82AAFF;">setState</span><span style="color:#F07178;">(</span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">()))</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> render</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapDispatchToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">WrapperComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{...</span><span style="color:#FFCB6B;">this</span><span style="color:#89DDFF;">.</span><span style="color:#FFCB6B;">props</span><span style="color:#89DDFF;">}</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{...</span><span style="color:#FFCB6B;">state</span><span style="color:#89DDFF;">}</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{...</span><span style="color:#FFCB6B;">dispatch</span><span style="color:#89DDFF;">}</span><span style="color:#F07178;"> /</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> }</span></span>
<span class="line"><span style="color:#F07178;"> }</span></span>
<span class="line"><span style="color:#F07178;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br></div></div><p>经过优化后，每次store.state发生变化会触发setState，由React内部的机制来决定组件是否应当重新渲染</p><p>如果组件依赖的state发生变化了，那么React会替我们执行re-render，而不是每次都强制执行re-render</p><p>进一步地，我们可以补充更多细节：</p><ul><li>当组件卸载时解除监听 <ul><li><code>store.subscribe</code>会返回一个<code>unsubscribe</code>函数 用于解除监听</li></ul></li><li>解除与业务代码store的耦合 <ul><li>目前的store来自业务代码 更优的做法是从context中动态获取到store</li><li>应当提供一个context Provider供用户使用</li><li>就像<code>react-redux</code>一样，使用connect前需要将App用Provider包裹并传入store</li></ul></li></ul><p>至此就基本完成了一个connect函数</p><div class="vp-code-group"><div class="tabs"><input type="radio" name="group-bT3DT" id="tab-Lh7DaIG" checked="checked"><label for="tab-Lh7DaIG">connect.js</label><input type="radio" name="group-bT3DT" id="tab-sAMSqyu"><label for="tab-sAMSqyu">storeContext.js</label><input type="radio" name="group-bT3DT" id="tab-cjoGGOs"><label for="tab-cjoGGOs">App.jsx</label></div><div class="blocks"><div class="language-tsx active line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// connect.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">StoreContext</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./storeContext</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">connect</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">mapStateToProps</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#A6ACCD;font-style:italic;">mapDispatchToProps</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">WrapperComponent</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">class</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">InnerComponent</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">extends</span><span style="color:#F07178;"> </span><span style="color:#FFCB6B;">PureComponent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">constructor</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">props</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;font-style:italic;">context</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">super</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">props</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">state</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">context</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> componentDidMount</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">unsubscribe</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">context</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">subscribe</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#82AAFF;">setState</span><span style="color:#F07178;">(</span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">context</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">()))</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> componentWillUnmount</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">this.</span><span style="color:#82AAFF;">unsubscribe</span><span style="color:#F07178;">()</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> render</span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">state</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapStateToProps</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">context</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">mapDispatchToProps</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">context</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">WrapperComponent</span><span style="color:#89DDFF;"> {...this.</span><span style="color:#A6ACCD;">props</span><span style="color:#89DDFF;">} {...</span><span style="color:#A6ACCD;">state</span><span style="color:#89DDFF;">} {...</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#89DDFF;">} /&gt;</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">InnerComponent</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">contextType</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">StoreContext</span></span>
<span class="line"></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">InnerComponent</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br><span class="line-number">24</span><br><span class="line-number">25</span><br><span class="line-number">26</span><br><span class="line-number">27</span><br><span class="line-number">28</span><br><span class="line-number">29</span><br><span class="line-number">30</span><br><span class="line-number">31</span><br><span class="line-number">32</span><br><span class="line-number">33</span><br><span class="line-number">34</span><br><span class="line-number">35</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// storeContext.js</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">createContext</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> StoreContext </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">createContext</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">null</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">const</span><span style="color:#A6ACCD;"> Provider </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> StoreContext</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">Provider</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div><div class="language-tsx line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">tsx</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// App.jsx</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> React</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Component</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">react</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> store </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./store</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> Counter </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./cpns/Counter</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">import</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">Provider</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">from</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">./hoc</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"></span>
<span class="line"><span style="color:#89DDFF;font-style:italic;">export</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;font-style:italic;">default</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">class</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">App</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">extends</span><span style="color:#A6ACCD;"> </span><span style="color:#FFCB6B;">Component</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#F07178;">render</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> (</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">Provider</span><span style="color:#89DDFF;"> </span><span style="color:#C792EA;">value</span><span style="color:#89DDFF;">={</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">}&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#F07178;">h1</span><span style="color:#89DDFF;">&gt;</span><span style="color:#A6ACCD;">React Redux</span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">h1</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;</span><span style="color:#FFCB6B;">Counter</span><span style="color:#89DDFF;"> /&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#F07178;">div</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">&lt;/</span><span style="color:#FFCB6B;">Provider</span><span style="color:#89DDFF;">&gt;</span></span>
<span class="line"><span style="color:#F07178;"> )</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br></div></div></div></div><h2 id="实现日志中间件logger" tabindex="-1">实现日志中间件logger <a class="header-anchor" href="#实现日志中间件logger" aria-label="Permalink to &quot;实现日志中间件logger&quot;">​</a></h2><p>设想现在有需求：设计一个Redux中间件，当我们每次通过dispatch派发action时都能够在控制台输出：派发了哪个action，传递的数据是怎样的</p><p>最终实现：拦截dispatch，并且在控制台打印派发的action</p><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// logger.js</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">logger</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">store</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">next</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;"> </span><span style="color:#676E95;font-style:italic;">// 保留原始的dispatch函数</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">function</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">dispatchWithLog</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">group</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">action</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">type</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">dispatching</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">res</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">next</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatch</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">next state</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">getState</span><span style="color:#F07178;">())</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">groupEnd</span><span style="color:#F07178;">()</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">res</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">dispatchWithLog</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#82AAFF;">logger</span><span style="color:#A6ACCD;">(store) </span><span style="color:#676E95;font-style:italic;">// 应用中间件</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br></div></div><p>通过<code>monkey patch</code>对原始dispatch函数进行了修改，为函数添加额外的副作用</p><h2 id="实现redux-thunk" tabindex="-1">实现redux-thunk <a class="header-anchor" href="#实现redux-thunk" aria-label="Permalink to &quot;实现redux-thunk&quot;">​</a></h2><p><code>redux-thunk</code>这个库帮我们提供了派发异步函数的功能</p><p>回顾一下<code>redux-thunk</code>的功能：</p><ul><li>默认情况下dispatch(action)的action必须为一个JS对象</li><li>redux-thunk允许我们传入一个函数作为action</li><li>函数会被调用，并且将dispatch函数和getState函数作为入参传递给这个函数action <ul><li>dispatch 允许我们在这之后再次派发action</li><li>getState 允许我们之后的一些操作依赖原来的状态，可以获取到之前的状态</li></ul></li></ul><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight has-highlighted-lines"><code><span class="line"><span style="color:#676E95;font-style:italic;">// thunk.js</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">thunk</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">store</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">const</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">next</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#C792EA;">function</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">dispatchWithThunk</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">action</span><span style="color:#89DDFF;">)</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">if</span><span style="color:#F07178;"> (</span><span style="color:#89DDFF;">typeof</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">===</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">function</span><span style="color:#89DDFF;">&#39;</span><span style="color:#F07178;">) </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#89DDFF;"> </span><span style="color:#676E95;font-style:italic;">// pass dispatch and getState to the thunk</span></span>
<span class="line highlighted"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">action</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">dispatch</span><span style="color:#89DDFF;">,</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">store</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">getState</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">next</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">action</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#89DDFF;font-style:italic;">return</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">dispatchWithThunk</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#82AAFF;">thunk</span><span style="color:#A6ACCD;">(store) </span><span style="color:#676E95;font-style:italic;">// 应用中间件</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br></div></div><p>需要注意的是，传递给函数action的第一个参数是经过更新后的新的<code>dispatch</code>函数，这是从细节考虑：如果在函数中又派发了函数</p><h2 id="实现applymiddleware" tabindex="-1">实现applyMiddleware <a class="header-anchor" href="#实现applymiddleware" aria-label="Permalink to &quot;实现applyMiddleware&quot;">​</a></h2><p>当我们需要同时应用多个中间件时，可以用<code>applyMiddleware</code>来对多个中间件进行组合，统一进行注册</p><div class="language-ts line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">ts</span><pre class="shiki material-theme-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// applyMiddleware.js</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">applyMiddleware</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">store</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">...</span><span style="color:#A6ACCD;font-style:italic;">fns</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">fns</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">forEach</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;font-style:italic;">fn</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">=&gt;</span><span style="color:#F07178;"> </span><span style="color:#82AAFF;">fn</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">store</span><span style="color:#F07178;">))</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"><span style="color:#82AAFF;">applyMiddleware</span><span style="color:#A6ACCD;">(store</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> logger</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> thunk) </span><span style="color:#676E95;font-style:italic;">// 使用applyMiddleware</span></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br></div></div></div></div></main><footer class="VPDocFooter" data-v-25140dfd data-v-b9eb50cb><!--[--><!--]--><div class="edit-info" data-v-b9eb50cb><div class="edit-link" data-v-b9eb50cb><a class="VPLink link edit-link-button" href="https://github.com/ZiuChen/ZiuChen.github.io/edit/main/docs/note/Redux.md" target="_blank" rel="noreferrer" data-v-b9eb50cb data-v-fd6e3585><!--[--><svg xmlns="http://www.w3.org/2000/svg" viewbox="0 0 24 24" class="edit-link-icon" aria-label="edit icon" data-v-b9eb50cb><path d="M18,23H4c-1.7,0-3-1.3-3-3V6c0-1.7,1.3-3,3-3h7c0.6,0,1,0.4,1,1s-0.4,1-1,1H4C3.4,5,3,5.4,3,6v14c0,0.6,0.4,1,1,1h14c0.6,0,1-0.4,1-1v-7c0-0.6,0.4-1,1-1s1,0.4,1,1v7C21,21.7,19.7,23,18,23z"></path><path d="M8,17c-0.3,0-0.5-0.1-0.7-0.3C7,16.5,6.9,16.1,7,15.8l1-4c0-0.2,0.1-0.3,0.3-0.5l9.5-9.5c1.2-1.2,3.2-1.2,4.4,0c1.2,1.2,1.2,3.2,0,4.4l-9.5,9.5c-0.1,0.1-0.3,0.2-0.5,0.3l-4,1C8.2,17,8.1,17,8,17zM9.9,12.5l-0.5,2.1l2.1-0.5l9.3-9.3c0.4-0.4,0.4-1.1,0-1.6c-0.4-0.4-1.2-0.4-1.6,0l0,0L9.9,12.5z M18.5,2.5L18.5,2.5L18.5,2.5z"></path></svg> Edit this page on GitHub<!--]--><!----></a></div><div class="last-updated" data-v-b9eb50cb><p class="VPLastUpdated" data-v-b9eb50cb data-v-f683efee>Updated Date: <time datetime="2023-05-12T02:57:41.000Z" data-v-f683efee></time></p></div></div><div class="prev-next" data-v-b9eb50cb><div class="pager" data-v-b9eb50cb><a class="pager-link prev" href="/note/React%20Hooks.html" data-v-b9eb50cb><span class="desc" data-v-b9eb50cb>Previous page</span><span class="title" data-v-b9eb50cb>React Hooks</span></a></div><div class="has-prev pager" data-v-b9eb50cb><a class="pager-link next" href="/note/React%20Router.html" data-v-b9eb50cb><span class="desc" data-v-b9eb50cb>Next page</span><span class="title" data-v-b9eb50cb>React Router</span></a></div></div></footer><!--[--><!--]--></div></div></div><!--[--><!--]--></div></div><footer class="VPFooter has-sidebar" data-v-6305e88a data-v-58542612><div class="container" data-v-58542612><p class="message" data-v-58542612>Released under the MIT License.</p><p class="copyright" data-v-58542612>Copyright © 2019-present Ziu Chen</p></div></footer><!--[--><!--]--></div></div>
<script>__VP_HASH_MAP__ = JSON.parse("{\"article_【字节跳动】前端面试题总结.md\":\"c7442fe7\",\"article_【快手】深入理解前端面试题.md\":\"e9e43d5f\",\"article_【用友金融】前端面试题总结.md\":\"fa6fbbd0\",\"article_一文读懂事件冒泡与事件捕获.md\":\"6009a5c1\",\"article_一文读懂伪类与伪元素.md\":\"b0832601\",\"article_一文读懂函数中this指向问题.md\":\"4e4bfdbd\",\"article_从0实现一个年度报告.md\":\"562144a4\",\"article_彻底搞懂对象的数据属性描述符、存储属性描述符.md\":\"b5517e81\",\"article_浅析defineproperty与proxy实现的双向绑定.md\":\"a9c9d501\",\"article_深入javascript数据类型.md\":\"9a0748e4\",\"article_深入vue3源码，看看vue.use后究竟发生了什么？.md\":\"4d017991\",\"article_深入理解proxy与reflect.md\":\"80dfcf88\",\"article_深入理解浏览器缓存机制.md\":\"b4469a93\",\"index.md\":\"6e541706\",\"article_深入理解浏览器运行原理.md\":\"a269bb9a\",\"note_front-end engineering.md\":\"aae64a89\",\"note_css.md\":\"6a456fcf\",\"note_javascript.md\":\"49645860\",\"article_【2023】青训营 - 前端练习题汇总解析.md\":\"eb23ed50\",\"note_react hooks.md\":\"a5dc7ac0\",\"project_jsrunner_index.md\":\"8e16292f\",\"project_clipboardmanager_index.md\":\"7f8a5976\",\"note_react router.md\":\"634ff014\",\"note_ssr.md\":\"7966fdeb\",\"project_clipboardmanager_guide_index.md\":\"e71cf377\",\"project_clipboardmanager_vip_index.md\":\"0c930f9b\",\"project_smartwordbreak_statement_index.md\":\"e24aa4c4\",\"project_jsrunner_log_index.md\":\"f460b67c\",\"project_markdown_index.md\":\"a908846d\",\"project_markdown_log_index.md\":\"8bd56850\",\"project_markdown_shortcut_index.md\":\"3afd587c\",\"project_smartwordbreak_index.md\":\"df8c04b0\",\"project_smartwordbreak_log_index.md\":\"efe8cdd1\",\"self_index.md\":\"1dbf6a78\",\"works_contribution.md\":\"bdfd51ae\",\"works_opensource.md\":\"c796986c\",\"note_mysql.md\":\"d3fb6382\",\"note_redux.md\":\"df821c9b\",\"project_clipboardmanager_log_index.md\":\"6dbaee0e\",\"project_clipboardmanager_statement_index.md\":\"7f23a234\",\"note_javascriptenhanced.md\":\"928d539f\",\"note_react.md\":\"9072d211\"}")
__VP_SITE_DATA__ = JSON.parse("{\"lang\":\"en-US\",\"dir\":\"ltr\",\"title\":\"ZiuChen\",\"description\":\"Unlimited Progress.\",\"base\":\"/\",\"head\":[],\"appearance\":true,\"themeConfig\":{\"logo\":\"/logo.png\",\"nav\":[{\"text\":\"首页\",\"link\":\"/\"},{\"text\":\"我的项目\",\"items\":[{\"text\":\"超级剪贴板\",\"link\":\"/project/ClipboardManager/\"},{\"text\":\"超级Markdown\",\"link\":\"/project/Markdown/\"},{\"text\":\"超级JavaScript\",\"link\":\"/project/JSRunner/\"},{\"text\":\"超级分词\",\"link\":\"/project/SmartWordBreak/\"}]},{\"text\":\"开源作品\",\"items\":[{\"text\":\"个人作品\",\"link\":\"/works/opensource\"},{\"text\":\"社区贡献\",\"link\":\"/works/contribution\"}]},{\"text\":\"学习笔记\",\"items\":[{\"text\":\"JavaScript基础\",\"link\":\"/note/JavaScript\"},{\"text\":\"CSS基础\",\"link\":\"/note/CSS\"},{\"text\":\"JavaScript进阶\",\"link\":\"/note/JavaScriptEnhanced\"},{\"text\":\"前端工程化\",\"link\":\"/note/Front-end Engineering\"},{\"text\":\"服务端渲染\",\"link\":\"/note/SSR\"},{\"text\":\"React基础\",\"link\":\"/note/React\"},{\"text\":\"React Hooks\",\"link\":\"/note/React Hooks\"},{\"text\":\"Redux\",\"link\":\"/note/Redux\"},{\"text\":\"React Router\",\"link\":\"/note/React Router\"},{\"text\":\"MySQL\",\"link\":\"/note/MySQL\"}]},{\"text\":\"个人介绍\",\"link\":\"/self/\"}],\"sidebar\":[{\"text\":\"我的项目\",\"items\":[{\"text\":\"超级剪贴板\",\"link\":\"/project/ClipboardManager/\"},{\"text\":\"超级Markdown\",\"link\":\"/project/Markdown/\"},{\"text\":\"超级JavaScript\",\"link\":\"/project/JSRunner/\"},{\"text\":\"超级分词\",\"link\":\"/project/SmartWordBreak/\"}]},{\"text\":\"开源作品\",\"collapsed\":true,\"items\":[{\"text\":\"个人作品\",\"link\":\"/works/opensource\"},{\"text\":\"社区贡献\",\"link\":\"/works/contribution\"}]},{\"text\":\"文章归档\",\"collapsed\":true,\"items\":[{\"text\":\"【2023】青训营 - 前端练习题汇总解析\",\"link\":\"/article/【2023】青训营 - 前端练习题汇总解析\"},{\"text\":\"【字节跳动】前端面试题总结\",\"link\":\"/article/【字节跳动】前端面试题总结\"},{\"text\":\"【快手】深入理解前端面试题\",\"link\":\"/article/【快手】深入理解前端面试题\"},{\"text\":\"【用友金融】前端面试题总结\",\"link\":\"/article/【用友金融】前端面试题总结\"},{\"text\":\"一文读懂事件冒泡与事件捕获\",\"link\":\"/article/一文读懂事件冒泡与事件捕获\"},{\"text\":\"一文读懂伪类与伪元素\",\"link\":\"/article/一文读懂伪类与伪元素\"},{\"text\":\"一文读懂函数中this指向问题\",\"link\":\"/article/一文读懂函数中this指向问题\"},{\"text\":\"从0实现一个年度报告\",\"link\":\"/article/从0实现一个年度报告\"},{\"text\":\"彻底搞懂对象的数据属性描述符、存储属性描述符\",\"link\":\"/article/彻底搞懂对象的数据属性描述符、存储属性描述符\"},{\"text\":\"浅析defineProperty与Proxy实现的双向绑定\",\"link\":\"/article/浅析defineProperty与Proxy实现的双向绑定\"},{\"text\":\"深入JavaScript数据类型\",\"link\":\"/article/深入JavaScript数据类型\"},{\"text\":\"深入Vue3源码，看看Vue.use后究竟发生了什么？\",\"link\":\"/article/深入Vue3源码，看看Vue.use后究竟发生了什么？\"},{\"text\":\"深入理解Proxy与Reflect\",\"link\":\"/article/深入理解Proxy与Reflect\"},{\"text\":\"深入理解浏览器缓存机制\",\"link\":\"/article/深入理解浏览器缓存机制\"},{\"text\":\"深入理解浏览器运行原理\",\"link\":\"/article/深入理解浏览器运行原理\"}]},{\"text\":\"学习笔记\",\"collapsed\":true,\"items\":[{\"text\":\"JavaScript基础\",\"link\":\"/note/JavaScript\"},{\"text\":\"CSS基础\",\"link\":\"/note/CSS\"},{\"text\":\"JavaScript进阶\",\"link\":\"/note/JavaScriptEnhanced\"},{\"text\":\"前端工程化\",\"link\":\"/note/Front-end Engineering\"},{\"text\":\"服务端渲染\",\"link\":\"/note/SSR\"},{\"text\":\"React基础\",\"link\":\"/note/React\"},{\"text\":\"React Hooks\",\"link\":\"/note/React Hooks\"},{\"text\":\"Redux\",\"link\":\"/note/Redux\"},{\"text\":\"React Router\",\"link\":\"/note/React Router\"},{\"text\":\"MySQL\",\"link\":\"/note/MySQL\"}]}],\"socialLinks\":[{\"icon\":\"github\",\"link\":\"https://github.com/ZiuChen\"},{\"icon\":{\"svg\":\"<svg width=\\\"36\\\" height=\\\"28\\\" viewBox=\\\"0 0 36 28\\\" fill=\\\"none\\\" xmlns=\\\"http://www.w3.org/2000/svg\\\"><path fill-rule=\\\"evenodd\\\" clip-rule=\\\"evenodd\\\" d=\\\"M17.5875 6.77268L21.8232 3.40505L17.5875 0.00748237L17.5837 0L13.3555 3.39757L17.5837 6.76894L17.5875 6.77268ZM17.5863 17.3955H17.59L28.5161 8.77432L25.5526 6.39453L17.59 12.6808H17.5863L17.5825 12.6845L9.61993 6.40201L6.66016 8.78181L17.5825 17.3992L17.5863 17.3955ZM17.5828 23.2891L17.5865 23.2854L32.2133 11.7456L35.1768 14.1254L28.5238 19.3752L17.5865 28L0.284376 14.3574L0 14.1291L2.95977 11.7531L17.5828 23.2891Z\\\" fill=\\\"#1E80FF\\\"/></svg>\"},\"link\":\"https://juejin.cn/user/1887205216238477\"}],\"editLink\":{\"pattern\":\"https://github.com/ZiuChen/ZiuChen.github.io/edit/main/docs/:path\",\"text\":\"Edit this page on GitHub\"},\"footer\":{\"message\":\"Released under the MIT License.\",\"copyright\":\"Copyright © 2019-present Ziu Chen\"},\"lastUpdatedText\":\"Updated Date\",\"search\":{\"provider\":\"algolia\",\"options\":{\"appId\":\"LFZ2CPWWUG\",\"apiKey\":\"b4fd296ea5e467b3ac4a582160ff3122\",\"indexName\":\"ziuchenio\"}}},\"locales\":{},\"scrollOffset\":90,\"cleanUrls\":false}")</script>
</body>
</html>
Reference in New Issue View Git Blame Copy Permalink