uTools-Manuals/docs/jQuery/even-selector.html
2019-04-21 11:50:48 +08:00

68 lines
7.3 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

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.

<article class="" id="post-">
<header class="entry-header">
<h1 class="entry-title">:even Selector</h1>
<div class="entry-meta">
所属分类:<span class="category"><a href="/category/selectors/">选择器</a> &gt; <a href="/category/selectors/basic-filter-selectors/">基础过滤</a></span><span class="category-divider"> | </span><span class="category"><a href="/category/selectors/">选择器</a> &gt; <a href="/category/selectors/jquery-selector-extensions/">jQuery 扩展</a></span>
<span class="pull-right">英文文档:<a href="https://api.jquery123.com/even-selector/" target="_blank">:even Selector</a></span>
</div><!-- .entry-meta -->
</header><!-- .entry-header -->
<!-- .entry-header -->
<div class="entry-content">
<article class="entry selector" id="even1"><h2 class="section-title"><span>even selector</span></h2>
<div class="entry-wrapper">
<p class="desc"><strong>描述: </strong>选择所引值为偶数的元素,从 0 开始计数。 也可以查看 <a href="/odd">odd</a>.</p>
<ul class="signatures"><li class="signature"><h4 class="name">
<span class="version-details">添加的版本: <a href="/category/version/1.0/">1.0</a></span>jQuery( ":even" )</h4></li></ul>
<div class="longdesc" id="entry-longdesc">
<p>特别地注意的是,这是<em>基于0的索引</em>,所以<code>:even</code>选择器是选择第一个元素,第三个元素,依此类推在匹配。</p>
</div>
<h3>Additional Notes:(其他注意事项:)</h3>
<div class="longdesc"><ul>
<li>
因为<code>:even</code> 是一个 jQuery 延伸出来的选择器并不是的CSS规范的一部分使用<code>:even</code> 查询不能充分利用原生DOM提供的<code>querySelectorAll()</code> 方法来提高性能。为了当使用<code>:even</code> 的时候在现代浏览器上获得更佳的性能首先使用纯CSS选择器选择元素然后使用<a href="/filter"><code>.filter(":even")</code></a>.
</li>
<li>查找表格中索引值是偶数的行(即实际表格中的奇数行),即匹配第一行、第三行、第五行等 (索引值是 0, 2 ,4 等 )。
</li>
</ul></div>
<section class="entry-examples" id="entry-examples"><header><h2 class="underline">例子:</h2></header><div class="entry-example" id="example-0">
<h4><span class="desc">Finds even table rows, matching the first, third and so on (index 0, 2, 4 etc.).</span></h4>
<div class="syntaxhighlighter xml ">
<table>
<tbody>
<tr>
<td class="gutter">
<div class="line n1">1</div>
<div class="line n2">2</div>
<div class="line n3">3</div>
<div class="line n4">4</div>
<div class="line n5">5</div>
<div class="line n6">6</div>
<div class="line n7">7</div>
<div class="line n8">8</div>
<div class="line n9">9</div>
<div class="line n10">10</div>
<div class="line n11">11</div>
<div class="line n12">12</div>
<div class="line n13">13</div>
<div class="line n14">14</div>
<div class="line n15">15</div>
<div class="line n16">16</div>
<div class="line n17">17</div>
<div class="line n18">18</div>
<div class="line n19">19</div>
<div class="line n20">20</div>
<div class="line n21">21</div>
<div class="line n22">22</div>
</td>
<td class="code">
<pre><div class="container"><div class="line"><code><span class="doctype">&lt;!DOCTYPE html&gt;</span></code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;<span class="title">html</span>&gt;</span></code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;<span class="title">head</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">style</span>&gt;</span><span class="css"></span></code></div></div><div class="container"><div class="line"><code> <span class="tag">table</span> <span class="rules">{</span></code></div></div><div class="container"><div class="line"><code> <span class="rule"><span class="attribute">background</span>:<span class="value"><span class="hexcolor">#eeeeee</span>;</span></span></code></div></div><div class="container"><div class="line"><code> <span class="rule">}</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;/<span class="title">style</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">script</span> <span class="attribute">src</span>=<span class="value">"https://code.jquery.com/jquery-latest.js"</span>&gt;</span><span class="javascript"></span><span class="tag">&lt;/<span class="title">script</span>&gt;</span></code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;/<span class="title">head</span>&gt;</span></code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;<span class="title">body</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">table</span> <span class="attribute">border</span>=<span class="value">"1"</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">tr</span>&gt;</span><span class="tag">&lt;<span class="title">td</span>&gt;</span>Row with Index #0<span class="tag">&lt;/<span class="title">td</span>&gt;</span><span class="tag">&lt;/<span class="title">tr</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">tr</span>&gt;</span><span class="tag">&lt;<span class="title">td</span>&gt;</span>Row with Index #1<span class="tag">&lt;/<span class="title">td</span>&gt;</span><span class="tag">&lt;/<span class="title">tr</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">tr</span>&gt;</span><span class="tag">&lt;<span class="title">td</span>&gt;</span>Row with Index #2<span class="tag">&lt;/<span class="title">td</span>&gt;</span><span class="tag">&lt;/<span class="title">tr</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;<span class="title">tr</span>&gt;</span><span class="tag">&lt;<span class="title">td</span>&gt;</span>Row with Index #3<span class="tag">&lt;/<span class="title">td</span>&gt;</span><span class="tag">&lt;/<span class="title">tr</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> <span class="tag">&lt;/<span class="title">table</span>&gt;</span></code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;<span class="title">script</span>&gt;</span><span class="javascript">$(<span class="string">"tr:even"</span>).css(<span class="string">"background-color"</span>, <span class="string">"#bbbbff"</span>);</span><span class="tag">&lt;/<span class="title">script</span>&gt;</span></code></div></div><div class="container"><div class="line"><code> </code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;/<span class="title">body</span>&gt;</span></code></div></div><div class="container"><div class="line"><code><span class="tag">&lt;/<span class="title">html</span>&gt;</span></code></div></div></pre>
</td>
</tr>
</tbody>
</table>
</div>
<h4>Demo:</h4>
<div class="demo code-demo"></div>
</div></section>
</div></article> </div>
</article>