From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- files/zh-cn/web/api/worker/onmessage/index.html | 124 ++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 files/zh-cn/web/api/worker/onmessage/index.html (limited to 'files/zh-cn/web/api/worker/onmessage/index.html') diff --git a/files/zh-cn/web/api/worker/onmessage/index.html b/files/zh-cn/web/api/worker/onmessage/index.html new file mode 100644 index 0000000000..9fb062c24f --- /dev/null +++ b/files/zh-cn/web/api/worker/onmessage/index.html @@ -0,0 +1,124 @@ +--- +title: Worker.onmessage +slug: Web/API/Worker/onmessage +translation_of: Web/API/Worker/onmessage +--- +

{{APIRef("Web Workers API")}}

+ +

{{domxref("Worker")}} 接口的onmessage属性表示一个{{domxref("EventHandler")}}事件处理函数，当{{event("message")}} 事件发生时，该函数被调用。这些事件所属{{domxref("MessageEvent")}}类型，且当Worker子线程返回一条消息时被调用（比如：从{{domxref("DedicatedWorkerGlobalScope.postMessage")}}函数发出的信息）

+ +
+

注意: 消息被装载到 {{event("message")}}事件对象的data属性。（译者：即传递的消息参数将被赋值给onmessage处理函数的事件参数e中的data属性）

+
+ +

语法

+ +
myWorker.onmessage = function(e) { ... }
+ +

范例

+ +

下面的代码片段示范用{{domxref("Worker.Worker", "Worker()")}} 构造函数创建一个{{domxref("Worker")}}对象。当表单的first输入框的值变更时，消息被传递给worker。myWorker.onmessage函数用来处理从worker回传的消息。

+ +
var myWorker = new Worker('worker.js');
+
+first.onchange = function() {
+  myWorker.postMessage([first.value,second.value]);
+  console.log('Message posted to worker');
+}
+
+myWorker.onmessage = function(e) {
+  result.textContent = e.data;
+  console.log('Message received from worker');
+}
+
+ +

在worker.js中,  onmessage 函数用来接收从主线程传递过来的信息:

+ +
onmessage = function(e) {
+  console.log('Message received from main script');
+  var workerResult = 'Result: ' + (e.data[0] * e.data[1]);
+  console.log('Posting message back to main script');
+  postMessage(workerResult);
+}
+ +

请注意，主线程中必须以myWorker.onmessage方式调用,  反之 worker.js 脚本中, 只需定义 onmessage, 因为worker.js全域有效({{domxref("DedicatedWorkerGlobalScope")}}).

+ +

完整范例，请参考Basic dedicated worker example (run dedicated worker).

+ +

规范

+ + + + + + + + + + + + + + + + + + + +
规范状态注释
{{SpecName('HTML WHATWG', "#handler-worker-onmessage", "Worker.onmessage")}}{{Spec2('HTML WHATWG')}}No change from {{SpecName("Web Workers")}}.
{{SpecName('Web Workers', "#handler-worker-onmessage", "Worker.onmessage")}}{{Spec2('Web Workers')}}Initial definition.
+ +

浏览器兼容性

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{{CompatibilityTable}}
+ +
+ + + + + + + + + + + + + + + + + + + +
特性ChromeFirefox (Gecko)Internet ExplorerOperaSafari (WebKit)
基本支持43.510.010.64
+
+ +
+ + + + + + + + + + + + + + + + + + + + + +
特性AndroidFirefox Mobile (Gecko)Firefox OS (Gecko)IE PhoneOpera MobileSafari Mobile
基本支持4.43.51.0.110.011.55.1
+
+ +

参阅

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{{domxref("Worker")}} 接口所属。

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