files/zh-cn/web/api/htmlmediaelement/audiotracks/index.html


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---
title: HTMLMediaElement.audioTracks
slug: Web/API/HTMLMediaElement/audioTracks
translation_of: Web/API/HTMLMediaElement/audioTracks
---
<div>{{APIRef("HTML DOM")}}</div>

<p> <strong><code>HTMLMediaElement.audioTracks</code></strong> 获得可用音频轨道的数量</p>

<h2 id="Syntax" name="Syntax">语法</h2>

<pre>audio|video.audioTracks</pre>

<h2 id="返回值">返回值</h2>

<p>AudioTrackList    对象 表示音频/视频的可用音频轨道</p>

<h2 id="用例">用例</h2>

<p>以audio标签为例</p>

<pre class="brush: html">&lt;audio id='audio'&gt;&lt;/audio&gt;
</pre>

<p>调用</p>

<pre>myVid=document.getElementById("audio");
alert(<code>myVid.audioTracks</code>.length);</pre>

<h2 id="参考文档">参考文档</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('HTML WHATWG', "the-video-element.html#htmlmediaelement", "HTMLMediaElement.audioTracks")}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td>No change from {{SpecName('HTML5 W3C')}}</td>
  </tr>
  <tr>
   <td>
    <p>{{SpecName('HTML5 W3C', "embedded-content-0.html#htmlmediaelement", "HTMLMediaElement.audioTracks")}}</p>
   </td>
   <td>{{Spec2('HTML5 W3C')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器支持">浏览器支持</h2>

<p>{{ CompatibilityTable() }}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td><code>audioTracks</code> property</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoDesktop("33.0")}}[5]</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>Firefox OS (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td><code>audioTracks</code> property</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoMobile("33.0")}}[5]</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="See_Also" name="See_Also">还可以看看</h2>

<ul>
 <li>定义它的接口, {{domxref("HTMLMediaElement")}}.</li>
</ul>