旋轉CamerePreviewImageSource

Question

我正在嘗試旋轉CameraPreviewImageSource以使其（僅）以縱向模式顯示：

    private async Task InitializeAsync()
    {
        this.cameraPreviewImageSource = new CameraPreviewImageSource();

        DeviceInformationCollection devices = await Windows.Devices.Enumeration.DeviceInformation.FindAllAsync(Windows.Devices.Enumeration.DeviceClass.VideoCapture);
        String backCameraId = devices.FirstOrDefault(x => x.EnclosureLocation != null && x.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back).Id;
        await cameraPreviewImageSource.InitializeAsync(backCameraId);

        VideoEncodingProperties properties = await this.cameraPreviewImageSource.StartPreviewAsync();

        double width = 1280;
        double height = 720;

        this.writeableBitmap = new WriteableBitmap( (int)width, (int)height );
        this.capturePreview.Source = this.writeableBitmap;

        this.writeableBitmapRenderer = new WriteableBitmapRenderer();
        this.jpegRenderer = new JpegRenderer();

        this.cameraPreviewImageSource.PreviewFrameAvailable += OnPreviewFrameAvailable;
    }

我也在XAML文件中嘗試過，但是大多數情況下結果很奇怪（例如90％的圖片被隱藏了）：

<Image x:Name="capturePreview" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="3" Grid.RowSpan="3" Width="auto"  Height="auto" Canvas.ZIndex="0" >
    <Image.RenderTransform>
        <CompositeTransform CenterX="0.5" CenterY="0.5" Rotation="90" />
    </Image.RenderTransform>
</Image> 

有任何想法嗎？

Answer 1

嘗試使用此開關Width和Height，並添加一個RotationFilter並將其旋轉設置為90。還將Device Orientation設置為Portrait 。 如果要在應用程序的其余部分中支持其他方向，只需在OnNavigatedTo / OnNavigatedFrom中設置Orientation 。

private async Task InitializeAsync()
{
    this.cameraPreviewImageSource = new CameraPreviewImageSource();

    DeviceInformationCollection devices = await Windows.Devices.Enumeration.DeviceInformation.FindAllAsync(Windows.Devices.Enumeration.DeviceClass.VideoCapture);
    String backCameraId = devices.FirstOrDefault(x => x.EnclosureLocation != null && x.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back).Id;
    await cameraPreviewImageSource.InitializeAsync(backCameraId);

    VideoEncodingProperties properties = await this.cameraPreviewImageSource.StartPreviewAsync();

    double width = 1280;
    double height = 720;

    this.writeableBitmap = new WriteableBitmap( (int)height, (int)width );
    this.capturePreview.Source = this.writeableBitmap;
    var effect = new FilterEffect(m_cameraPreviewImageSource);
    effect.Filters = new IFilter[] { new RotationFilter(90) };

    this.writeableBitmapRenderer = new WriteableBitmapRenderer(effect);
    this.jpegRenderer = new JpegRenderer();

    this.cameraPreviewImageSource.PreviewFrameAvailable += OnPreviewFrameAvailable;
}


protected override void OnNavigatedTo(NavigationEventArgs e)
{
    m_displayOrientations = DisplayInformation.AutoRotationPreferences;
    DisplayInformation.AutoRotationPreferences = DisplayOrientations.Portrait;
    NavigationHelper.OnNavigatedTo(e);
}

protected override void OnNavigatedFrom(NavigationEventArgs e)
{
    DisplayInformation.AutoRotationPreferences = m_displayOrientations;
    NavigationHelper.OnNavigatedFrom(e);
}

Answer 2

由於您使用諾基亞影像SDK來實現此目的，您是否嘗試過在渲染鏈中添加RotateFilter並在需要時進行旋轉？

您的鏈將是：CameraPreviewSource-> FilterEffect [rotateFilter]-> WriteableBitmapRenderer。