XAML Unleashed

Writing Pixel Data

BitmapEncoder exposes a SetPixelData method that is analogous to the more complex overload of BitmapDecoder’s GetPixelDataAsync method. In addition to passing a flattened byte array (with pixels in row-major order), you must specify everything needed for the encoder to interpret the array: the pixel format, alpha mode, width, and height. You must also provide DPI values for both dimensions (or 0 to omit that metadata). The following implementation of UseEncoder creates a red-blue gradient image exactly like the one created with WriteableBitmap in Figure 11.4:

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async Task UseEncoder(BitmapEncoder encoder){  const int PixelWidth = 1024;  const int PixelHeight = 728;  const int BytesPerPixel = 4;