在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

MediaTrackSettings dictionary's aspectRatio property is a double-precision floating-point number indicating the aspect ratio of the MediaStreamTrack as currently configured. This lets you determine what value was selected to comply with your specified constraints for this property's value as described in the MediaTrackConstraints.aspectRatio property you provided when calling either getUserMedia() or MediaStreamTrack.applyConstraints() .

If needed, you can determine whether or not this constraint is supported by checking the value of MediaTrackSupportedConstraints.aspectRatio as returned by a call to MediaDevices.getSupportedConstraints() . However, typically this is unnecessary since browsers will simply ignore any constraints they're unfamiliar with.

句法

var aspectRatio = MediaTrackSettings.aspectRatio;
					

值

A double-precision floating-point number indicating the current configuration of the track's aspect ratio. The aspect ratio is computed by taking the track's width, dividing by its height, and rounding the result to ten decimal places. For example, the standard 16:9 high-definition aspect ratio can be computed as 1920/1080, or 1.7777777778.

范例

见 Example: Constraint exerciser in Capabilities, constraints, and settings 范例。

规范

规范	状态	注释
媒体捕获和流 The definition of 'aspectRatio' in that specification.	候选推荐	最初的规范。

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
aspectRatio	Chrome Yes	Edge ≤79	Firefox No	IE ?	Opera Yes	Safari ?	WebView Android Yes	Chrome Android Yes	Firefox Android No	Opera Android Yes	Safari iOS ?	Samsung Internet Android Yes

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

• Media Capture and Streams API
• Capabilities, constraints, and settings
• MediaTrackConstraints.aspectRatio
• MediaTrackSettings

元数据

• 最后修改： 2020 年 1 月 22 日

相关话题

1. Media Streams API
2. MediaTrackSettings
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
   17. width
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. MediaTrackSupportedConstraints
   18. Navigator.mediaDevices
   19. NavigatorUserMedia
   20. NavigatorUserMediaError
   21. VideoStreamTrack
   22. navigator.mediaDevices.getUserMedia()