Event.timeStamp

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句法
范例
Reduced time precision
规范
浏览器兼容性
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timeStamp 只读特性在 事件 interface returns the time (in milliseconds) at which the event was created.

注意： This property only works if the event system supports it for the particular event.

句法

time = event.timeStamp;

值

This value is the number of milliseconds elapsed from the beginning of the current document's lifetime till the event was created.

In newer implementations, the value is a DOMHighResTimeStamp accurate to 5 microseconds (0.005 ms). In older implementations, the value is a DOMTimeStamp , accurate to a millisecond.

范例

HTML

<p>
  Focus this iframe and press any key to get the
  current timestamp for the keypress event.
</p>
<p>timeStamp: <span id="time">-</span></p>

JavaScript

function getTime(event) {
  var time = document.getElementById("time");
  time.firstChild.nodeValue = event.timeStamp;
}
document.body.addEventListener("keypress", getTime);

结果

Reduced time precision

To offer protection against timing attacks and fingerprinting, the precision of Event.timeStamp might get rounded depending on browser settings.

In Firefox, the privacy.reduceTimerPrecision preference is enabled by default and defaults to 20us in Firefox 59; in 60 it will be 2ms.

// reduced time precision (2ms) in Firefox 60
event.timeStamp;
// 1519211809934
// 1519211810362
// 1519211811670
// ...
// reduced time precision with `privacy.resistFingerprinting` enabled
event.timeStamp;
// 1519129853500
// 1519129858900
// 1519129864400
// ...

In Firefox, if you also enable privacy.resistFingerprinting , the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds , whichever is larger.

规范

规范	状态	注释
DOM The definition of 'Event.timeStamp' 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
`timeStamp`	Chrome 49 49 Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Edge 12	Firefox Yes Yes Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	IE Yes Yes Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Opera 36 36 Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Safari Yes	WebView Android 49 49 Starting with version 49, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Chrome Android 49 49 Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Firefox Android Yes Yes Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Opera Android 36 36 Starting with Chrome 49, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .	Safari iOS Yes	Samsung Internet Android 5.0 5.0 Starting with Samsung Internet 5.0, Firefox 54 and Opera 36, this property returns `DOMHighResTimeStamp` 而不是 `DOMTimeStamp` .

图例

完整支持

元数据

最后修改： Aug 25, 2020

DOM (文档对象模型)
事件
构造函数
1. 事件
特性
1. bubbles
2. cancelable
3. cancelBubble
4. composed
5. currentTarget
6. defaultPrevented
7. eventPhase
8. explicitOriginalTarget
9. isTrusted
10. originalTarget
11. returnValue
12. srcElement
13. target
14. timeStamp
15. type
方法
事件
1. bubbles
2. cancelable
3. cancelBubble
4. composed
5. composedPath
6. currentTarget
7. defaultPrevented
8. 事件
9. eventPhase
10. initEvent
11. isTrusted
12. preventDefault
13. returnValue
14. stopImmediatePropagation
15. stopPropagation
16. target
17. timeStamp
18. type
DOM 相关页面

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句法

值

范例

HTML

JavaScript

结果

Reduced time precision

规范

浏览器兼容性

图例

相关话题