---
title: MessageChannel.port1
slug: Web/API/MessageChannel/port1
translation_of: Web/API/MessageChannel/port1
---
<div>{{APIRef("HTML DOM")}}</div>

<p>{{domxref("MessageChannel")}} 的只读属性 <code><strong>port1 </strong>返回消息通道的第一个端口</code>, 此端口连接到源上下文通道。</p>

<p>{{AvailableInWorkers}}</p>

<h2 id="语法">语法</h2>

<pre class="syntaxbox">channel.port1;</pre>

<h3 id="Value">Value</h3>

<p>一个 {{domxref("MessagePort")}} 对象, 通道的第一个端口，此端口连接到源上下文通道。</p>

<h2 id="示例">示例</h2>

<p>在以下代码块中，您可以看到使用 {{domxref("MessageChannel.MessageChannel", "MessageChannel()")}}构造函数创建的新通道。当{{HTMLElement("iframe")}}加载完毕，我们使用{{domxref("MessagePort.postMessage")}}方法把一条消息和{{domxref("MessageChannel.port2")}}传递给{{HTMLElement("iframe")}}。handleMessage处理程序将会从&lt;iframe&gt;中（使用{{domxref("MessagePort.onmessage")}}监听事件）接收到信息，将数据其放入一个段落。handleMessage 方法关联到 port1用于监听收到的消息。</p>

<pre class="brush: js;highlight[13]">var channel = new MessageChannel();
var para = document.querySelector('p');

var ifr = document.querySelector('iframe');
var otherWindow = ifr.contentWindow;

ifr.addEventListener("load", iframeLoaded, false);

function iframeLoaded() {
  otherWindow.postMessage('Hello from the main page!', '*', [channel.port2]);
}

channel.port1.onmessage = handleMessage;
function handleMessage(e) {
  para.innerHTML = e.data;
}
</pre>

<p>一个完整的运行示例，可以在Github上查看 <a class="external external-icon" href="https://github.com/mdn/channel-messaging-basic-demo">channel messaging basic demo</a>  (<a class="external external-icon" href="http://mdn.github.io/channel-messaging-basic-demo/">run it live too</a>).</p>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">规范</th>
   <th scope="col">状态</th>
   <th scope="col">备注</th>
  </tr>
  <tr>
   <td>{{SpecName('HTML WHATWG', '#dom-messagechannel-port1','port1')}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td>No difference from {{SpecName("HTML5 Web Messaging")}}.</td>
  </tr>
  <tr>
   <td>{{SpecName('HTML5 Web Messaging', '#dom-messagechannel-port1','port1')}}</td>
   <td>{{Spec2('HTML5 Web Messaging')}}</td>
   <td>W3C version of the spec</td>
  </tr>
 </tbody>
</table>

<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>Feature</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari (WebKit)</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>4</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoDesktop(41)}}</td>
   <td>10.0</td>
   <td>10.6</td>
   <td>5</td>
  </tr>
  <tr>
   <td>Available in workers</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoDesktop(41)}}</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>Firefox OS (Gecko)</th>
   <th>IE Phone</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>4.4</td>
   <td>4</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoMobile(41)}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>10.0</td>
   <td>11.5</td>
   <td>5.1</td>
  </tr>
  <tr>
   <td>Available in workers</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoMobile(41)}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="参考">参考</h2>

<ul>
 <li><a href="/en-US/docs/Web/API/Channel_Messaging_API/Using_channel_messaging">Using channel messaging</a></li>
</ul>