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• 特性
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

ConstrainULong type is used to specify a constraint for a property whose value is an integral number. It extends the ULongRange dictionary (which provides the ability to specify a permitted range of property values) to also support an exact value and/or an ideal value the property should take on. In addition, you can specify the value as a simple long integer value, in which case the user agent does its best to match the value once all other more stringent constraints are met.

特性

If the value of a ConstrainULong is an object rather than a number, it may have the properties below in addition to the properties it inherits from ULongRange .

exact

An integer specifying precise, required, value the property must have to be considered acceptable.

ideal

An integer specifying a value the property would ideally have, but which can be considered optional if necessary to find a match.

规范

规范	状态	注释
媒体捕获和流 The definition of 'ConstrainULong' in that specification.	候选推荐	初始定义

Technically, ConstrainULong is actually based on an intermediary dictionary named ConstrainULongRange , which adds exact and ideal to ULongRange ，采用 ConstrainULong being a type that can be either a long integer or a ULongRange . However, for the sake of documentation clarity, the intermediate type (present only because of quirks in WebIDL syntax) is ignored here.

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
ConstrainULong	Chrome No	Edge No	Firefox No	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android No	Opera Android No	Safari iOS No	Samsung Internet Android No

图例

不支持

不支持

另请参阅

• Media Capture and Streams API
• Capabilities, constraints, and settings
• ULongRange
• MediaTrackConstraints
• MediaTrackCapabilities
• MediaTrackSupportedConstraints

元数据

• 最后修改： Jan 25, 2020

相关话题

1. Media Streams API
2. ConstrainULong
3. 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. MediaTrackSupportedConstraints
   19. Navigator.mediaDevices
   20. NavigatorUserMedia
   21. NavigatorUserMediaError
   22. VideoStreamTrack
   23. navigator.mediaDevices.getUserMedia()