---
title: MediaStream.addTrack()
slug: Web/API/MediaStream/addTrack
translation_of: Web/API/MediaStream/addTrack
original_slug: Web/API/MediaStream.addTrack
---
<p>{{APIRef("Media Capture and Streams")}}</p>

<p><strong><code>MediaStream.addTrack()</code></strong> 方法会给流添加一个新轨道。指定一个{{domxref("MediaStreamTrack")}}对象作为参数。</p>

<div class="note">
<p>如果指定的track已经存在于流的track set里的话，该方法不会产生作用。</p>
</div>

<h2 id="语法">语法</h2>

<pre class="syntaxbox"><em>stream</em>.addTrack(<em>track</em>);
</pre>

<h3 id="Parameters">Parameters</h3>

<dl>
 <dt><code>track</code></dt>
 <dd>A {{domxref("MediaStreamTrack")}} to add to the stream.</dd>
</dl>

<h2 id="Example">Example</h2>

<p> </p>

<h2 id="Specifications" name="Specifications">Specifications</h2>

<table class="standard-table" style="height: 49px; width: 1000px;">
 <thead>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{ SpecName('Media Capture','#widl-MediaStream-addTrack-void-MediaStreamTrack-track','addTrack()') }}</td>
   <td>{{ Spec2('Media Capture') }}</td>
   <td>Initial specification.</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

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

<div id="compat-desktop">{{ CompatUnknown() }}
<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>Basic support</td>
   <td>{{ CompatVersionUnknown() }}</td>
   <td>{{ CompatGeckoDesktop(34) }}</td>
   <td>{{ CompatNo() }}</td>
   <td>{{ CompatVersionUnknown() }}</td>
   <td>{{ CompatUnknown() }}</td>
  </tr>
  <tr>
   <td><code>addTrack()</code> and {{domxref("removeTrack()")}}</td>
   <td>{{ CompatUnknown() }}</td>
   <td>{{CompatGeckoDesktop(44)}}</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>Chrome for Android</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>{{ CompatGeckoMobile(34) }}</td>
   <td>{{ CompatNo() }}</td>
   <td>{{ CompatUnknown() }}</td>
   <td>{{ CompatUnknown() }}</td>
  </tr>
  <tr>
   <td><code>addTrack()</code> and {{domxref("removeTrack()")}}</td>
   <td>{{ CompatUnknown() }}</td>
   <td>{{CompatGeckoDesktop(44)}}</td>
   <td>{{ CompatUnknown() }}</td>
   <td>{{ CompatUnknown() }}</td>
   <td>{{ CompatUnknown() }}</td>
   <td>{{ CompatUnknown() }}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="See_also">See also</h2>

<ul>
 <li>{{domxref("MediaStream")}}, the interface it belongs to.</li>
</ul>