MediaTrackConstraints.cursor

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句法
用法注意事项
范例
规范
浏览器兼容性
另请参阅
相关话题

MediaTrackConstraints dictionary's cursor 特性为 ConstrainDOMString describing the requested or mandatory constraints placed upon the value of the cursor constrainable property, which is used to specify whether or not the cursor should be included in the captured video.

If needed, you can determine whether or not this constraint is supported by checking the value of MediaTrackSupportedConstraints.cursor 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 constraintsObject = { cursor: constraint };
constraintsObject.cursor = constraint;

值

A ConstrainDOMString which specifies whether or not the mouse cursor should be rendered into the video track in the MediaStream returned by the call to getDisplayMedia() 。见 How constraints are defined in Capabilities, constraints, and settings for an explanation of how to define constraints.

用法注意事项

You can check the setting selected by the user agent after the display media has been created by getDisplayMedia() 通过调用 getSettings() on the display media's video MediaStreamTrack , then checking the value of the returned MediaTrackSettings 对象的 cursor 对象。

For example, if your app needs to alter the stream by inserting a representation of the cursor position if the stream doesn't include the rendered cursor, you can determine the need to do so by using code like this:

let insertFakeCursorFlag = false;
if (displayStream.getVideoTracks()[0].getSettings().cursor === "never") {
  insertFakeCursorFlag = true;
}

Following this code, insertFakeCursorFlag is true if there's no cursor rendered into the stream already. Later code can detect this flag's value and if it's true , can manually look at some metadata that might be provided and insert a fake representation of the cursor at the correct position.

范例

Here are some example constraints objects for getDisplayMedia() that make use of the cursor property. In addition, see Example: Constraint exerciser in Capabilities, constraints, and settings for a complete example showing how constraints are used.

Example: Cursor always visible

This example sets up the constraints to request that the cursor always be visible.

let displayMediaOptions = {
  cursor: "always"
};

Example: Cursor visible during motion with fallback

在此范例中， cursor property is configured to request that the cursor be visible when in motion, falling back to always being visible if the user agent doesn't support in-motion only cursor rendering.

let displayMediaOptions = {
  cursor: ["motion", "always"]
};

Example: Require that the cursor not be visible

This constraints object explicitly requires that the cursor not be rendered into the video track.

let displayMediaOptions = {
  cursor: {
    exact: "none"
  }
};

规范

规范	状态	注释
Screen Capture The definition of 'MediaTrackConstraints.cursor' in that specification.	未知	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
`cursor`	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
不支持
兼容性未知 ?

另请参阅

元数据

最后修改： May 13, 2019

Media Streams API
MediaTrackConstraints
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. logicalSurface
14. noiseSuppression
15. sampleRate
16. sampleSize
17. volume
18. width
Related pages for Media Capture and Streams

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句法

值