0 out of 11 rated this helpful - Rate this topic

WriteableBitmap.PixelBuffer property

Gets an access for the direct buffer where each pixel of the WriteableBitmap is written to.

Syntax


public IBuffer PixelBuffer { get; }

Property value

Type: IBuffer

A reference to the pixel buffer.

Remarks

PixelBuffer cannot be written to directly, however, you can use language-specific techniques to access the buffer and change its contents.

To access the pixel content from C# or Microsoft Visual Basic, you can use the AsStream extension method to access the underlying buffer as a stream.
To access the pixel content from C++, you can query for the IBufferByteAccess type (defined in Robuffer.h) and directly access its Buffer property.

Examples

This example writes to the PixelBuffer property of WriteableBitmap as part of a transcoding scenario that will eventually use the WriteableBitmap as an Image.Source value and display the image. The code shown here comes from a larger code sample, the SDK XAML images sample.


using (IRandomAccessStream fileStream = await file.OpenAsync(Windows.Storage.FileAccessMode.Read)) 
{
    BitmapDecoder decoder = await BitmapDecoder.CreateAsync(fileStream); 
    // Scale image to appropriate size 
    BitmapTransform transform = new BitmapTransform() {  
        ScaledWidth = Convert.ToUInt32(Scenario4WriteableBitmap.PixelWidth), 
        ScaledHeight = Convert.ToUInt32(Scenario4WriteableBitmap.PixelHeight)
    }; 
    PixelDataProvider pixelData = await decoder.GetPixelDataAsync( 
        BitmapPixelFormat.Bgra8, // WriteableBitmap uses BGRA format 
        BitmapAlphaMode.Straight, 
        transform, 
        ExifOrientationMode.IgnoreExifOrientation, // This sample ignores Exif orientation 
        ColorManagementMode.DoNotColorManage
    ); 
 
    // An array containing the decoded image data, which could be modified before being displayed 
    byte[] sourcePixels = pixelData.DetachPixelData(); 
 
    // Open a stream to copy the image contents to the WriteableBitmap's pixel buffer 
    using (Stream stream = Scenario4WriteableBitmap.PixelBuffer.AsStream()) 
    { 
        await stream.WriteAsync(sourcePixels, 0, sourcePixels.Length); 
    }                     
}

Requirements