h5开启手机闪关灯代码

以下是开启手机闪光灯的H5代码:

if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
  navigator.mediaDevices.getUserMedia({
    video: true
  }).then(function(stream) {
    var track = stream.getVideoTracks()[0];
    var imageCapture = new ImageCapture(track);
    var photoSettings = {
      fillLightMode: 'flash'
    };
    imageCapture.getPhotoCapabilities().then(function(capabilities) {
      if (!capabilities.fillLightSupported) {
        console.log('Flash not supported on this device');
        return;
      }
      imageCapture.setOptions(photoSettings).then(function() {
        track.applyConstraints({
          advanced: [{
            torch: true
          }]
        });
      });
    });
  });
} else {
  console.log('getUserMedia() is not supported');
}

但请注意，该代码只适用于支持torch功能的设备。