---
title: MouseEvent.movementX
slug: Web/API/MouseEvent/movementX
translation_of: Web/API/MouseEvent/movementX
---
<p>{{APIRef("DOM Events")}}</p>

<p> <strong><code>MouseEvent.movementX</code></strong> 是只读属性，它提供了当前事件和上一个{{event("mousemove")}}事件之间鼠标在水平方向上的移动值。换句话说，这个值是这样计算的 : <code>currentEvent.movementX = currentEvent.screenX - previousEvent.screenX</code>.</p>

<h2 id="语法">语法</h2>

<pre class="syntaxbox">var <em>xShift</em> = <em>instanceOfMouseEvent</em>.movementX
</pre>

<h3 id="返回值">返回值</h3>

<p>一个数字</p>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Pointer Lock','#widl-MouseEvent-movementX','MouseEvent.movementX')}}</td>
   <td>{{Spec2('Pointer Lock')}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility" name="Browser_compatibility">浏览器兼容性</h2>

{{Compat("api.MouseEvent.movementX")}}

<h2 id="See_also" name="See_also">相关</h2>

<ul>
 <li>{{ domxref("MouseEvent") }}</li>
 <li><a href="/en-US/docs/WebAPI/Pointer_Lock">Pointer Lock</a></li>
</ul>