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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

MediaTrackSupportedConstraints dictionary's logicalSurface property indicates whether or not the logicalSurface constraint is supported by the user agent and the device on which the content is being used.

The supported constraints list is obtained by calling navigator.mediaDevices.getSupportedConstraints() .

句法

isLogicalSurfaceSupported = supportedConstraints.logicalSurface;
					

值

A Boolean value which is true 若 logicalSurface constraint is supported by the device and user agent.

范例

This method sets up the constraints object specifying the options for the call to getDisplayMedia() . It adds the logicalSurface constraint (requesting that only logical display surfaces—those which may not be entirely visible onscreen—be included among the options available to the user) only if it is known to be supported by the browser. Capturing is then started by calling getDisplayMedia() and attaching the returned stream to the video element referenced by the variable videoElem .

async function capture() {
  let supportedConstraints = navigator.mediaDevices.getSupportedConstraints();
  let displayMediaOptions = {
    video: {
    },
    audio: false;
  };
  if (supportedConstraints.logicalSurface) {
    displayMediaOptions.video.logicalSurface = "monitor";
  }
  try {
    videoElem.srcObject = await navigator.mediaDevices.getDisplayMedia(displayMediaOptions);
  } catch(err) {
    /* handle the error */
  }
}
					

规范

规范	状态	注释
Screen Capture The definition of 'MediaTrackSupportedConstraints.logicalSurface' in that specification.	工作草案	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
logicalSurface	Chrome No	Edge No	Firefox No	IE No	Opera Yes	Safari ?	WebView Android No	Chrome Android No	Firefox Android No	Opera Android ?	Safari iOS ?	Samsung Internet Android No

图例

完整支持

完整支持

不支持

不支持

兼容性未知 ?

兼容性未知

另请参阅

• Screen Capture API
• Using the screen capture API
• Capabilities, constraints, and settings
• MediaDevices.getDisplayMedia()
• MediaStreamTrack.getConstraints()
• MediaStreamTrack.applyConstraints()
• MediaStreamTrack.getSettings()

元数据

• 最后修改： Dec 23, 2019

相关话题

1. Media Streams API
2. MediaTrackSupportedConstraints
3. 特性

   1. aspectRatio
   2. autoGainControl
   3. channelCount
   4. cursor
   5. deviceId
   6. displaySurface
   7. echoCancellation
   8. facingMode
   9. frameRate
   10. groupId
   11. height
   12. latency
   13. noiseSuppression
   14. sampleRate
   15. sampleSize
   16. volume
4. 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. MediaDevices
   12. MediaStream
   13. MediaStreamTrack
   14. MediaStreamTrackEvent
   15. MediaTrackCapabilities
   16. MediaTrackConstraints
   17. MediaTrackSettings
   18. Navigator.mediaDevices
   19. NavigatorUserMedia
   20. NavigatorUserMediaError
   21. VideoStreamTrack
   22. navigator.mediaDevices.getUserMedia()