window.requestIdleCallback()

在此页

句法
范例
规范
浏览器兼容性
另请参阅
相关话题

这是实验性技术
检查浏览器兼容性表格要小心谨慎在生产中使用这之前。

window.requestIdleCallback() method queues a function to be called during a browser's idle periods. This enables developers to perform background and low priority work on the main event loop, without impacting latency-critical events such as animation and input response. Functions are generally called in first-in-first-out order; however, callbacks which have a timeout specified may be called out-of-order if necessary in order to run them before the timeout elapses.

可以调用 requestIdleCallback() within an idle callback function to schedule another callback to take place no sooner than the next pass through the event loop.


							timeout

option is strongly recommended for required work, as otherwise it's possible multiple seconds will elapse before the callback is fired.

句法

var handle = window.requestIdleCallback(callback[, options])

返回值

An ID which can be used to cancel the callback by passing it into the window.cancelIdleCallback() 方法。

参数

callback

A reference to a function that should be called in the near future, when the event loop is idle. The callback function is passed an


									IdleDeadline

object describing the amount of time available and whether or not the callback has been run because the timeout period expired.

选项 可选

Contains optional configuration parameters. Currently only one property is defined:

timeout ：若 timeout is specified and has a positive value, and the callback has not already been called by the time timeout milliseconds have passed, the callback will be called during the next idle period, even if doing so risks causing a negative performance impact.

范例

See our complete example in the article Cooperative Scheduling of Background Tasks API .

规范

规范	状态	注释
Cooperative Scheduling of Background Tasks	Proposed Recommendation	初始定义。

浏览器兼容性

The compatibility table in 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
`requestIdleCallback`	Chrome 47	Edge 79	Firefox 55 55 Enabled by default. 不支持 53 — 55 Implemented but disabled by default.	IE No	Opera 34	Safari No	WebView Android 47	Chrome Android 47	Firefox Android 55 55 Enabled by default. 不支持 53 — 55 Implemented but disabled by default.	Opera Android 34	Safari iOS No	Samsung Internet Android 5.0

在此页

句法

返回值

参数

范例

规范

浏览器兼容性

图例

另请参阅

元数据

相关话题