MessageChannel.port2

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句法
范例
规范
浏览器兼容性
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port2 只读特性在 MessageChannel interface returns the second port of the message channel — the port attached to the context at the other end of the channel, which the message is initially sent to.

注意： 此特征可用于 Web 工作者 .

句法

channel.port2;

值

A MessagePort object representing the second port of the channel, the port attached to the context at the other end of the channel.

范例

In the following code block, you can see a new channel being created using the MessageChannel.MessageChannel constructor. When the IFrame has loaded, we pass port2 to the IFrame using MessagePort.postMessage along with a message. The handleMessage handler then responds to a message being sent back from the IFrame (using MessagePort.onmessage ), putting it into a paragraph. MessageChannel.port1 is listened to, to check when the message arrives.

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;
}

For a full working example, see our channel messaging basic demo on Github ( run it live too ).

规范

规范	状态	注释
HTML 实时标准 The definition of 'port2' in that specification.	实时标准

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`port2`	Chrome 4	Edge 12	Firefox 41	IE 10	Opera 10.6	Safari 5	WebView Android 4.4	Chrome Android 18	Firefox Android 41	Opera Android 11	Safari iOS 5.1	Samsung Internet Android 1.0

图例

完整支持

另请参阅

Using channel messaging

元数据

最后修改： Jan 17, 2020

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句法

值

范例

规范

浏览器兼容性

图例

另请参阅

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