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

<p><strong><code>MouseEvent.movementY</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.movementY = currentEvent.screenY - previousEvent.screenY</code>.</p>

<h2 id="语法">语法</h2>

<pre class="syntaxbox">var <em>yShift</em> = <em>instanceOfMouseEvent</em>.movementY
</pre>

<h3 id="返回值">返回值</h3>

<p>A number</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-movementY','MouseEvent.movementY')}}</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.movementY")}}

<h2 id="相关">相关</h2>

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