在windows 8.1商店应用程序中找不到前后摄像头

本文关键字：找不到 摄像头 应用程序 windows | 更新日期: 2023-09-27 18:26:08

我已经开发了windows 8.1商店应用程序，它需要使用后置摄像头和post来拍摄照片。

MediaCaptureInitializationSettings _captureSettings = new var devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
    foreach (var device in devices)
    {
    if (device.EnclosureLocation != null && device.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back)
                        {
                            deviceId = device.Id;
                            break;
                        }
                    }
  if (!string.IsNullOrEmpty(deviceId))
                    {
                        _captureSettings.AudioDeviceId = "";
                        _captureSettings.VideoDeviceId = deviceId;
                        _captureSettings.PhotoCaptureSource = Windows.Media.Capture.PhotoCaptureSource.Photo;
                        _captureSettings.StreamingCaptureMode = Windows.Media.Capture.StreamingCaptureMode.Video;
                    }
captureManager = new MediaCapture();
await captureManager.InitializeAsync(_captureSettings);
                    await captureManager.ClearEffectsAsync(MediaStreamType.Photo);
                    capturePreview1.Source = captureManager;
                    await captureManager.StartPreviewAsync();
</code>
Here i am getting two devices but that devices EnclosureLocation is null, so i can't find which one is front and back camera.
so have decided to get second device from list 
<code>
deviceId = devices[1].Id;
</code>
but it throws an error like "The current capture source does not have an independent photo stream."
in the line of initializing MediaCapture
<code>
await captureManager.InitializeAsync(_captureSettings);
</code>


    
我在windowssurfacepro2和acer设备上试过。请告知。提前谢谢。

  
在windows 8.1商店应用程序中找不到前后摄像头

试着更好地组织代码，因为同一行有两个等号，而且代码格式不好，所以很难阅读。

要在Windows 8.1停止应用程序中使用相机，我使用此代码：

// First need to find all webcams
DeviceInformationCollection webcamList = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture)
// Then I do a query to find the front webcam
DeviceInformation frontWebcam = (from webcam in webcamList
 where webcam.EnclosureLocation != null 
 && webcam.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Front
 select webcam).FirstOrDefault();
// Same for the back webcam
DeviceInformation backWebcam = (from webcam in webcamList
 where webcam.EnclosureLocation != null 
 && webcam.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back
 select webcam).FirstOrDefault();
// Then you need to initialize your MediaCapture
var captureManager = new MediaCapture();
await captureManager.InitializeAsync(new MediaCaptureInitializationSettings
{
    // Choose the webcam you want (backWebcam or frontWebcam)
    VideoDeviceId = backWebcam.Id,
    AudioDeviceId = "",
    StreamingCaptureMode = StreamingCaptureMode.Video,
    PhotoCaptureSource = PhotoCaptureSource.VideoPreview
});
// Set the source of the CaptureElement to your MediaCapture
capturePreview1.Source = captureManager;
// Start the preview
await captureManager.StartPreviewAsync();

这样更容易阅读。代码差别不大，MediaCaptureInitializationSettings也不一样。

这个代码在Surface 2 RT和诺基亚635上对我有效，所以它应该对你有效。

编辑：

它似乎适用于带有Windows RT的设备，但在完整的Windows 8.1设备上，它总是为空。Msdn说：

如果没有可用的机柜位置信息，则该属性将为空

所以你能做的是首先试着看看你是否找到了一个后台摄像头，如果它是空的，就拿最后一个；

DeviceInformation backWebcam = (from webcam in webcamList
 where webcam.EnclosureLocation != null 
 && webcam.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back
 select webcam).FirstOrDefault();
if (backWebcam == null)
{
   backWebcam = webcamList.Last();
}

但你不确定集合中的最后一个是后面的，所以你应该添加一个按钮，让用户切换相机

如果你更换相机，

await captureManager.StopPreviewAsync();
await captureManager.InitializeAsync(new MediaCaptureInitializationSettings
    {
        // Choose an other webcam 
        VideoDeviceId = //id of the new webcam,
        AudioDeviceId = "",
        StreamingCaptureMode = StreamingCaptureMode.Video,
        PhotoCaptureSource = PhotoCaptureSource.VideoPreview
    });
 await captureManager.StartPreviewAsync();

这样你就可以确保用户可以选择正确的相机，即使你在编程上无法判断哪一个是

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