只读
didTimeout
property on the
IdleDeadline
interface is a Boolean value which indicates whether or not the idle callback is being invoked because the timeout interval specified when
Window.requestIdleCallback()
was called has expired.
若
didTimeout
is
true
，
IdleDeadline
对象的
timeRemaining()
method will return approximately 0.
Idle callbacks support the concept of a timeout in order to ensure that whatever task they're meant to perform actually happens, even if the user agent never has enough idle time available. Your callback will typically check the value of
didTimeout
if it needs to perform an action even if the browser is too busy to grant you the time; you should react by performing the needed task or, ideally, a minimal amount of work that can be done to keep things moving along, then schedule a new callback to try again to get the rest of the work done.
var timedOut = IdleDeadline.didTimeout;
A Boolean which is
true
if the callback is running due to the callback's timeout period elapsing or
false
if the callback is running because the user agent is idle and is offering time to the callback.
See our complete example in the article Cooperative Scheduling of Background Tasks API .
| 规范 | 状态 | 注释 |
|---|---|---|
| Cooperative Scheduling of Background Tasks | Proposed Recommendation |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
didTimeout
|
Chrome 47 | Edge 79 |
Firefox
55
|
IE 不支持 No | Opera 34 | Safari 不支持 No | WebView Android 47 | Chrome Android 47 |
Firefox Android
55
|
Opera Android 34 | Safari iOS 不支持 No | Samsung Internet Android 5.0 |
完整支持
不支持
用户必须明确启用此特征。
IdleDeadline
Window.requestIdleCallback()
Window.cancelIdleCallback()
IdleDeadline
didTimeout