Window: unhandledrejection event

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用法注意事项
范例
规范
浏览器兼容性
另请参阅
相关话题

unhandledrejection event is sent to the global scope of a script when a JavaScript Promise that has no rejection handler is rejected; typically, this is the window , but may also be a Worker . This is useful for debugging and for providing fallback error handling for unexpected situations.

冒泡	No
可取消	Yes
接口	`PromiseRejectionEvent`
事件处理程序特性	`onunhandledrejection`

用法注意事项

Allowing the unhandledrejection event to bubble will eventually result in an error message being output to the console. You can prevent this by calling preventDefault() 在 PromiseRejectionEvent ；见 Preventing default handling below for an example.

范例

Here we have a few examples showing ways you can make use of the unhandledrejection event. The event includes two useful pieces of information:

promise: 实际 Promise which was rejected with no handler available to deal with the rejection.
reason: The reason that would have been passed into the rejection handler if one had existed. See catch() 了解细节。

Basic error logging

This example simply logs information about the unhandled promise rejection to the console.

window.addEventListener("unhandledrejection", event => {
  console.warn(`UNHANDLED PROMISE REJECTION: ${event.reason}`);
});

还可以使用 onunhandledrejection event handler property to set up the event listener:

window.onunhandledrejection = event => {
  console.warn(`UNHANDLED PROMISE REJECTION: ${event.reason}`);
};

Preventing default handling

Many environments (such as Node.js ) report unhandled promise rejections to the console by default. You can prevent that from happening by adding a handler for unhandledrejection events that—in addition to any other tasks you wish to perform—calls preventDefault() to cancel the event, preventing it from bubbling up to be handled by the runtime's logging code. This works because unhandledrejection is cancelable.

window.addEventListener('unhandledrejection', function (event) {
  // ...your code here to handle the unhandled rejection...
  // Prevent the default handling (such as outputting the
  // error to the console)
  event.preventDefault();
});

规范

规范	状态	注释
HTML 实时标准 The definition of 'unhandledrejection' in that specification.	实时标准	初始定义。

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
`unhandledrejection` event	Chrome 49	Edge ≤79	Firefox 69 69 Disabled ). To change preferences in Firefox, visit	IE No	Opera 36	Safari 11	WebView Android 49	Chrome Android 49	Firefox Android 68	Opera Android 36	Safari iOS 11.3	Samsung Internet Android 5.0

图例

完整支持
不支持
用户必须明确启用此特征。

另请参阅

承诺拒绝事件 in Using Promises
onunhandledrejection event handler property ¹
rejectionhandled event
Promise

[1] The corresponding event handler property is defined on the WindowEventHandlers mixin, which is available on both the Window interface and all types of Worker 接口。

元数据

最后修改： Jun 13, 2020

在此页

用法注意事项

范例

Basic error logging

Preventing default handling

规范

浏览器兼容性

图例

另请参阅

相关话题