如何在Windows 10 Universal App中切换到后置摄像头

Question

我似乎无法找到MediaCapture类的属性，它允许我检测Surface中的后置和前置摄像头，如果Combobox Items可用，则切换到它。这是我当前设备的设置。

        mc = new MediaCapture();
        DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);

        // Use the front camera if found one
        if (devices == null) return;
        var info = devices[0];

        //var rearCamera;
        //DeviceInformation info2 = devices[1];

        foreach (var devInfo in devices)
        {
            if (devInfo.Name.ToLowerInvariant().Contains("front"))
            {

                info = devInfo;
                //info2 = devInfo;
                //frontCam = true;
                //backCam = true;
                camera = true;
                //continue;
            }
            if (devInfo.Name.ToLowerInvariant().Contains("back"))
            {
                var rearCamera = devices[1];
                rearCamera = devInfo;
            }
        }

        await mc.InitializeAsync(new MediaCaptureInitializationSettings
            {
            MediaCategory = MediaCategory.Communications,
            StreamingCaptureMode = StreamingCaptureMode.AudioAndVideo,
            VideoDeviceId = info.Id,
                //VideoDeviceId = info2.Id
            });


        DisplayInformation displayInfo = DisplayInformation.GetForCurrentView();
        displayInfo.OrientationChanged += DisplayInfo_OrientationChanged;
        DisplayInfo_OrientationChanged(displayInfo, null);

        stream = new InMemoryRandomAccessStream();
        llmr = await mc.PrepareLowLagRecordToStreamAsync(MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto), stream);
        await llmr.StartAsync();
        await llmr.StopAsync();


        CaptureElement.Source = mc;
        CaptureElement.FlowDirection = camera ? FlowDirection.RightToLeft : FlowDirection.LeftToRight;
        CaptureStack.Visibility = Visibility.Visible;
        CameraErrorTextBlock.Visibility = Visibility.Collapsed;
        RecordProgress.Visibility = Visibility.Visible;
        CaptureGrid.Visibility = Visibility.Visible;
        CancelButton.HorizontalAlignment = HorizontalAlignment.Right;
        //CaptureElement.FlowDirection = FlowDirection.LeftToRight;

        // prepare low lag recording
        stream = new InMemoryRandomAccessStream();
        llmr = await mc.PrepareLowLagRecordToStreamAsync(MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto), stream);



        await mc.StartPreviewAsync();

Answer 1

您需要使用所需相机设备的VideoDeviceId（从DeviceInformationCollection设备获取）再次运行MediaCapture.InitializeAsync。然后将CaptureElement.Source设置为新的MediaCapture。

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Answer 2

您应该使用DeviceInformation的 ＆＃34; EnclosureLocation＆＃34; 属性。

var allVideoDevices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
// Get the desired camera by panel
DeviceInformation cameraDevice =
    allVideoDevices.FirstOrDefault(x => x.EnclosureLocation != null &&
    x.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back);

Windows.Devices.Enumeration.Panel.Back 将成为后置摄像头的EnclosureLocation。