在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 相关话题

PerformanceObserver() 构造函数创建新 PerformanceObserver object with the given observer callback . The observer callback is invoked when performance entry events are recorded for the entry types that have been registered, via the observe() 方法。

句法

var observer = new PerformanceObserver(callback);
					

参数

callback

A PerformanceObserverCallback callback that will be invoked when observed performance events are recorded. When the callback is invoked, its first parameter is a list of performance observer entries and the second parameter is the observer 对象。

返回值

新的 PerformanceObserver object which will call the specified callback when observed performance events occur.

范例

var observer = new PerformanceObserver(function(list, obj) {
  var entries = list.getEntries();
  for (var i=0; i < entries.length; i++) {
    // Process "mark" and "frame" events
  }
});
observer.observe({entryTypes: ["mark", "frame"]});
function perf_observer(list, observer) {
  // Process the "measure" event
}
var observer2 = new PerformanceObserver(perf_observer);
observer2.observe({entryTypes: ["measure"]});
					

规范

规范	状态	注释
Performance Timeline Level 2 The definition of 'PerformanceObserver()' in that specification.	候选推荐	Initial definition of PerformanceObserver() 构造函数。

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
PerformanceObserver() 构造函数	Chrome 52	Edge ≤79	Firefox 57	IE 不支持 No	Opera 39	Safari 11	WebView Android 52	Chrome Android 52	Firefox Android 57	Opera Android 41	Safari iOS 11	Samsung Internet Android 6.0

图例

完整支持

完整支持

不支持

不支持

元数据

• 最后修改： 2019 年 3 月 23 日

相关话题

1. 性能时间线
2. PerformanceObserver
3. 构造函数

   1. PerformanceObserver()
4. 方法

   1. disconnect()
   2. observe()
   3. takeRecords()
5. Related pages for Performance Timeline API

   1. 性能
   2. PerformanceEntry
   3. PerformanceObserverEntryList
   4. PerformanceResourceTiming
   5. Window.performance