---
title: focus
slug: Web/API/Element/focus_event
translation_of: Web/API/Element/focus_event
original_slug: Web/Events/focus
---
<p>focus事件在元素获取焦点时触发. 这个事件和 <a href="/en-US/docs/Mozilla_event_reference/focusin"><code>focusin</code></a> 最大的区别仅仅在于后者会事件冒泡.</p>

<h2 id="基本信息">基本信息</h2>

<dl>
 <dt style="float: left; text-align: right; width: 120px;">规范</dt>
 <dd style="margin: 0 0 0 120px;"><a class="external" href="http://www.w3.org/TR/DOM-Level-3-Events/#event-type-focus">DOM L3</a></dd>
 <dt style="float: left; text-align: right; width: 120px;">接口</dt>
 <dd style="margin: 0 0 0 120px;">{{ domxref("FocusEvent") }}</dd>
 <dt style="float: left; text-align: right; width: 120px;">是否冒泡</dt>
 <dd style="margin: 0 0 0 120px;">否</dd>
 <dt style="float: left; text-align: right; width: 120px;">能否取消默认</dt>
 <dd style="margin: 0 0 0 120px;">否</dd>
 <dt style="float: left; text-align: right; width: 120px;">事件目标</dt>
 <dd style="margin: 0 0 0 120px;">Element</dd>
 <dt style="float: left; text-align: right; width: 120px;">默认行为</dt>
 <dd style="margin: 0 0 0 120px;">无.</dd>
</dl>

<div class="note">注释: 这里的接口是指 {{ domxref("Event") }} prior to Gecko 24 {{ geckoRelease(24) }}. ({{ bug(855741) }})</div>

<h2 id="属性">属性</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">Property</th>
   <th scope="col">Type</th>
   <th scope="col">Description</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><code>target</code> {{readonlyInline}}</td>
   <td>{{domxref("EventTarget")}}</td>
   <td>Event target (DOM element)</td>
  </tr>
  <tr>
   <td><code>type</code> {{readonlyInline}}</td>
   <td>{{domxref("DOMString")}}</td>
   <td>The type of event.</td>
  </tr>
  <tr>
   <td><code>bubbles</code> {{readonlyInline}}</td>
   <td>{{jsxref("Boolean")}}</td>
   <td>Whether the event normally bubbles or not.</td>
  </tr>
  <tr>
   <td><code>cancelable</code> {{readonlyInline}}</td>
   <td>{{jsxref("Boolean")}}</td>
   <td>Whether the event is cancellable or not.</td>
  </tr>
  <tr>
   <td><code>relatedTarget</code> {{readonlyInline}}</td>
   <td>{{domxref("EventTarget")}} (DOM element)</td>
   <td>null</td>
  </tr>
 </tbody>
</table>

<h2 id="事件委托">事件委托</h2>

<p>此事件有两个可以实现事件委托的方法 : 通过在支持的浏览器上使用 <code>focusin</code> 事件 (除了Firefox之外的所有浏览器), 或者通过设置 <a href="/en-US/docs/DOM/element.addEventListener"><code>addEventListener</code></a> 的参数"useCapture" 值为true:</p>

<p>{{ EmbedLiveSample('Event_delegation', '', '', '', 'Web/Events/blur') }}</p>

<p>(Sample code from <a href="/en-US/docs/Web/Events/blur">blur (event)</a>)</p>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Featrue</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatVersionUnknown()}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown()}}</td>
   <td>{{CompatVersionUnknown()}}</td>
   <td>{{CompatVersionUnknown()}}</td>
   <td>{{CompatVersionUnknown()}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatUnknown()}}</td>
   <td>{{CompatUnknown()}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown()}}</td>
   <td>{{CompatUnknown()}}</td>
   <td>{{CompatUnknown()}}</td>
   <td>{{CompatUnknown()}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="相关事件">相关事件</h2>

<ul>
 <li>{{event("focus")}}</li>
 <li>{{event("blur")}}</li>
 <li>{{event("focusin")}}</li>
 <li>{{event("focusout")}}</li>
</ul>