打开/关闭闪光灯

Posted 2023-04-12

【中文标题】打开/关闭闪光灯

【英文标题】：Turn Flash On/Off

【发布时间】：2013-06-20 00:06:42

【问题描述】：

好的，我的问题很简单。

我已经成功地打开了闪光灯（并保持打开状态）。

但是，我仍然不确定如何将其关闭（笑）。

这是我的代码：

var sensorLocation = CameraSensorLocation.Back;

try

    // get the AudioViceoCaptureDevice
    var avDevice = await AudioVideoCaptureDevice.OpenAsync(sensorLocation,
        AudioVideoCaptureDevice.GetAvailableCaptureResolutions(sensorLocation).First());

    // turn flashlight on
    var supportedCameraModes = AudioVideoCaptureDevice
        .GetSupportedPropertyValues(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchMode);
    if (supportedCameraModes.ToList().Contains((UInt32)VideoTorchMode.On))
    
        avDevice.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.On);

        // set flash power to maxinum
        avDevice.SetProperty(KnownCameraAudioVideoProperties.VideoTorchPower,
            AudioVideoCaptureDevice.GetSupportedPropertyRange(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchPower).Max);
    
    else
    
        turnWhiteScreen(true);
    


catch (Exception ex)

    // Flashlight isn't supported on this device, instead show a White Screen as the flash light
    turnWhiteScreen(true);

有什么想法吗？

---

附言

我原以为将.ons 转换为.offs 可以，但它没有。 已在 HTC 8S 和 Lumia 820 上进行了测试。

【参考方案1】：

您似乎无法两次检索采集设备（我不确定为什么），因此您应该将其存储在一个属性中：

protected AudioVideoCaptureDevice Device  get; set; 

private async void ButtonTurnOn_Click(object sender, RoutedEventArgs e)

    var sensorLocation = CameraSensorLocation.Back;

    try
    
        if (this.Device == null)
        
            // get the AudioViceoCaptureDevice
            this.Device = await AudioVideoCaptureDevice.OpenAsync(sensorLocation,
            AudioVideoCaptureDevice.GetAvailableCaptureResolutions(sensorLocation).First());
        

        // turn flashlight on
        var supportedCameraModes = AudioVideoCaptureDevice
            .GetSupportedPropertyValues(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchMode);
        if (supportedCameraModes.ToList().Contains((UInt32)VideoTorchMode.On))
        
            this.Device.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.On);

            // set flash power to maxinum
            this.Device.SetProperty(KnownCameraAudioVideoProperties.VideoTorchPower,
                AudioVideoCaptureDevice.GetSupportedPropertyRange(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchPower).Max);
        
        else
        
            turnWhiteScreen(true);
        

    
    catch (Exception ex)
    
        // Flashlight isn't supported on this device, instead show a White Screen as the flash light
        turnWhiteScreen(true);
    

然后，将其关闭：

private void ButtonTurnOff_Click(object sender, RoutedEventArgs e)

    var sensorLocation = CameraSensorLocation.Back;

    try
    
        // turn flashlight on
        var supportedCameraModes = AudioVideoCaptureDevice
            .GetSupportedPropertyValues(sensorLocation, KnownCameraAudioVideoProperties.VideoTorchMode);
        if (this.Device != null && supportedCameraModes.ToList().Contains((UInt32)VideoTorchMode.Off))
        
            this.Device.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.Off);
        
        else
        
            turnWhiteScreen(false);
        
    
    catch (Exception ex)
    
        // Flashlight isn't supported on this device, instead show a White Screen as the flash light
        turnWhiteScreen(false);
    

【讨论】：

嗯，这太棒了——而且如此简单！ 有效！非常感谢，伙计！ ;-)

【参考方案2】：

试试这个

private static VideoTorchMode _videoTorchMode = VideoTorchMode.Off;
private AudioVideoCaptureDevice _videoRecordingDevice;

检查手电筒是否存在于设备中。

private async void CheckTorch() 
  if(AudioVideoCaptureDevice.AvailableSensorLocations.Contains(CameraSensorLocation.Back) &&
      AudioVideoCaptureDevice.GetSupportedPropertyValues(CameraSensorLocation.Back, KnownCameraAudioVideoProperties.VideoTorchMode).ToList().Contains((UInt32)VideoTorchMode.On)) 
     var temp = AudioVideoCaptureDevice.GetAvailableCaptureResolutions(CameraSensorLocation.Back)[0];
     var resolution = new Windows.Foundation.Size(temp .Width, temp .Height);
     _videoRecordingDevice = await AudioVideoCaptureDevice.OpenAsync(CameraSensorLocation.Back, resolution);
    
   else
     MessageBox.Show("Your device does not support torch");

改变手电筒状态

private void SetTorchMode()   
   try 
     if (BackgroundHandler.Instance.IsBackTorchExist) 
        if (_videoTorchMode == VideoTorchMode.Off) 
           _videoRecordingDevice.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.On);
           _videoTorchMode = VideoTorchMode.On;
         
         else 
            _videoRecordingDevice.SetProperty(KnownCameraAudioVideoProperties.VideoTorchMode, VideoTorchMode.Off);
            _videoTorchMode = VideoTorchMode.Off;                                    
         
      
   
   catch (Exception ex)