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---
title: MutationObserver
slug: Web/API/MutationObserver
tags:
- API
- Advanced
- DOM
- DOM Reference
- MutationObserver
- requestAnimationFrame
- resize
translation_of: Web/API/MutationObserver
---
<p>{{APIRef("DOM WHATWG")}}</p>
<p>{{domxref("MutationObserver")}}接口提供了监视对DOM树所做更改的能力。它被设计为旧的Mutation Events功能的替代品，该功能是DOM3 Events规范的一部分。</p>
<h2 id="构造函数">构造函数</h2>
<dl>
<dt>{{domxref("MutationObserver.MutationObserver", "MutationObserver()")}}</dt>
<dd>创建并返回一个新的 <code>MutationObserver</code> 它会在指定的DOM发生变化时被调用。</dd>
</dl>
<h2 id="Instance_methods" name="Instance_methods">方法</h2>
<dl>
<dt>{{domxref("MutationObserver.disconnect", "disconnect()")}}</dt>
<dd><code><font face="Open Sans, arial, x-locale-body, sans-serif"><span style="background-color: #ffffff;">阻止 </span></font>MutationObserver</code> 实例继续接收的通知，直到再次调用其{{domxref("MutationObserver.observe", "observe()")}}方法，该观察者对象包含的回调函数都不会再被调用。</dd>
<dt>{{domxref("MutationObserver.observe", "observe()")}}</dt>
<dd>配置<code>MutationObserver</code>在DOM更改匹配给定选项时，通过其回调函数开始接收通知。</dd>
<dt>{{domxref("MutationObserver.takeRecords", "takeRecords()")}}</dt>
<dd>从MutationObserver的通知队列中删除所有待处理的通知，并将它们返回到{{domxref("MutationRecord")}}对象的新{{jsxref("Array")}}中。</dd>
</dl>
<h2 id="Mutation_Observer_customize_resize_event_listener_demo">Mutation Observer & customize resize event listener & demo</h2>
<p><a href="https://codepen.io/webgeeker/full/YjrZgg/">https://codepen.io/webgeeker/full/YjrZgg/</a></p>
<h2 id="示例">示例</h2>
<p>以下示例改编自<a href="http://hacks.mozilla.org/2012/05/dom-mutationobserver-reacting-to-dom-changes-without-killing-browser-performance/">这篇博客</a>。</p>
<pre class="brush: js notranslate">// 选择需要观察变动的节点
const targetNode = document.getElementById('some-id');
// 观察器的配置（需要观察什么变动）
const config = { attributes: true, childList: true, subtree: true };
// 当观察到变动时执行的回调函数
const callback = function(mutationsList, observer) {
// Use traditional 'for loops' for IE 11
for(let mutation of mutationsList) {
if (mutation.type === 'childList') {
console.log('A child node has been added or removed.');
}
else if (mutation.type === 'attributes') {
console.log('The ' + mutation.attributeName + ' attribute was modified.');
}
}
};
// 创建一个观察器实例并传入回调函数
const observer = new MutationObserver(callback);
// 以上述配置开始观察目标节点
observer.observe(targetNode, config);
// 之后，可停止观察
observer.disconnect();
</pre>
<ul>
</ul>
<h2 id="Specifications" name="Specifications">规范</h2>
<table class="standard-table">
<thead>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">注释</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{SpecName('DOM WHATWG', '#mutationobserver', 'MutationObserver')}}</td>
<td>{{ Spec2('DOM WHATWG') }}</td>
<td></td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容">浏览器兼容</h2>
<p>{{Compat("api.MutationObserver")}}</p>
<h2 id="参见">参见</h2>
<ul>
<li>{{domxref('PerformanceObserver')}}</li>
<li>{{domxref('ResizeObserver')}}</li>
<li>{{domxref('IntersectionObserver')}}</li>
<li><a href="http://updates.html5rocks.com/2012/02/Detect-DOM-changes-with-Mutation-Observers" rel="freelink">A brief overview</a></li>
<li><a href="http://hacks.mozilla.org/2012/05/dom-mutationobserver-reacting-to-dom-changes-without-killing-browser-performance/" rel="freelink">A more in-depth discussion</a></li>
<li><a href="http://www.youtube.com/watch?v=eRZ4pO0gVWw" rel="freelink">A screencast by Chromium developer Rafael Weinstein</a></li>
</ul>
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