MediaDevices.enumerateDevices()

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MediaDevices 方法 enumerateDevices() requests a list of the available media input and output devices, such as microphones, cameras, headsets, and so forth. 返回的 Promise is resolved with a MediaDeviceInfo array describing the devices.

句法

var enumeratorPromise = navigator.mediaDevices.enumerateDevices();

返回值

A Promise that receives an array of MediaDeviceInfo objects when the promise is fulfilled. Each object in the array describes one of the available media input and output devices.

If enumeration fails, the promise is rejected.

范例

此处范例，使用 enumerateDevices() . It simply outputs a list of the device IDs , with their labels if available.

if (!navigator.mediaDevices || !navigator.mediaDevices.enumerateDevices) {
  console.log("enumerateDevices() not supported.");
  return;
}
// List cameras and microphones.
navigator.mediaDevices.enumerateDevices()
.then(function(devices) {
  devices.forEach(function(device) {
    console.log(device.kind + ": " + device.label +
                " id = " + device.deviceId);
  });
})
.catch(function(err) {
  console.log(err.name + ": " + err.message);
});

This might produce:

videoinput: id = csO9c0YpAf274OuCPUA53CNE0YHlIr2yXCi+SqfBZZ8=
audioinput: id = RKxXByjnabbADGQNNZqLVLdmXlS0YkETYCIbg+XxnvM=
audioinput: id = r2/xw1xUPIyZunfV1lGrKOma5wTOvCkWfZ368XCndm0=

or if one or more MediaStream s are active or persistent permissions are granted:

videoinput: FaceTime HD Camera (Built-in) id=csO9c0YpAf274OuCPUA53CNE0YHlIr2yXCi+SqfBZZ8=
audioinput: default (Built-in Microphone) id=RKxXByjnabbADGQNNZqLVLdmXlS0YkETYCIbg+XxnvM=
audioinput: Built-in Microphone id=r2/xw1xUPIyZunfV1lGrKOma5wTOvCkWfZ368XCndm0=

规范

规范	状态	注释
媒体捕获和流 The definition of 'mediaDevices: enumerateDevices' 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
`enumerateDevices`	Chrome 47	Edge 12	Firefox 63 Disabled 63 Disabled Prior to Firefox 63, `enumerateDevices()` only returned input devices. Starting with Firefox 63, output devices are also included if the `media.setsinkid.enabled` preference is enabled. Disabled From version 63: this feature is behind the `media.setsinkid.enabled` preference (needs to be set to `true` ). To change preferences in Firefox, visit about:config. 39	IE No	Opera 34	Safari 11	WebView Android 47	Chrome Android 47	Firefox Android 63 Disabled 63 Disabled Prior to Firefox 63, `enumerateDevices()` only returned input devices. Starting with Firefox 63, output devices are also included if the `media.setsinkid.enabled` preference is enabled. Disabled From version 63: this feature is behind the `media.setsinkid.enabled` preference (needs to be set to `true` ). To change preferences in Firefox, visit about:config. 39	Opera Android 34	Safari iOS 11	Samsung Internet Android 5.0

图例

完整支持
不支持

用户必须明确启用此特征。

另请参阅

navigator.mediaDevices.getUserMedia()
WebRTC - the introductory page to the API
MediaStream API - the API for the media stream objects
Taking webcam photos - a tutorial on using getUserMedia() for taking photos rather than video.

元数据

最后修改： Mar 18, 2019

WebRTC API
MediaDevices
特性
1. ondevicechange
方法
1. enumerateDevices()
2. getDisplayMedia()
3. getSupportedConstraints()
4. getUserMedia()
继承：
1. EventTarget
Related pages for WebRTC

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句法

返回值

范例

规范

浏览器兼容性

图例

另请参阅

相关话题