打开/关闭闪光灯

Question

好的,我的问题很简单.

我已经设法打开闪光灯(并保持打开).

但是,我仍然不确定如何关闭它(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);
}

有任何想法吗？

---

PS

• 我想像将.ons 转换为.offs可能有效,但事实并非如此.
• 这已经在HTC 8S和Lumia 820上进行了测试.

Answer 1

看起来你无法检索两次采集设备(我不知道为什么),所以你应该将它存储在一个属性中:

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);
    }
}