在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 相关话题

getSupportedConstraints () 方法在 MediaDevices interface returns an object based on the MediaTrackSupportedConstraints dictionary, whose member fields each specify one of the constrainable properties the 用户代理 understands.

句法

var supportedConstraints = navigator.mediaDevices.getSupportedConstraints();
					

参数

None.

返回值

A new object based on the MediaTrackSupportedConstraints dictionary listing the constraints supported by the user agent. Because only constraints supported by the user agent are included in the list, each of these Boolean properties has the value true .

范例

This example outputs a list of the constraints supported by your browser.

HTML

<p>The following media constraints are supported by your browser:</p>
<ul id="constraintList">
</ul>
					

CSS

body {
  font: 15px Arial, sans-serif;
}
					

JavaScript

let constraintList = document.getElementById("constraintList");
let supportedConstraints = navigator.mediaDevices.getSupportedConstraints();
for (let constraint in supportedConstraints) {
  if (supportedConstraints.hasOwnProperty(constraint)) {
    let elem = document.createElement("li");
    elem.innerHTML = "<code>" + constraint + "</code>";
    constraintList.appendChild(elem);
  }
}
					

结果

规范

规范	状态	注释
媒体捕获和流 The definition of 'getSupportedConstraints()' in that specification.	候选推荐	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
getSupportedConstraints	Chrome 53	Edge 12	Firefox 44	IE No	Opera 40	Safari 11	WebView Android 53	Chrome Android 52	Firefox Android 50	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： 2020 年 1 月 22 日

相关话题

1. Media Streams API
2. MediaDevices
3. 特性

   1. ondevicechange
4. 方法

   1. enumerateDevices()
   2. getDisplayMedia()
   3. getSupportedConstraints()
   4. getUserMedia()
5. 继承：

   1. EventTarget
6. Related pages for Media Capture and Streams

   1. AudioStreamTrack
   2. BlobEvent
   3. CanvasCaptureMediaStream
   4. ConstrainBoolean
   5. ConstrainDOMString
   6. ConstrainDouble
   7. ConstrainLong
   8. DoubleRange
   9. HTMLCanvasElement.captureStream()
   10. LongRange
   11. MediaStream
   12. MediaStreamTrack
   13. MediaStreamTrackEvent
   14. MediaTrackCapabilities
   15. MediaTrackConstraints
   16. MediaTrackSettings
   17. MediaTrackSupportedConstraints
   18. Navigator.mediaDevices
   19. NavigatorUserMedia
   20. NavigatorUserMediaError
   21. VideoStreamTrack
   22. navigator.mediaDevices.getUserMedia()