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wpfbitmapsourcedrawingbrush

How do I convert from a Brush (e.g. DrawingBrush) to a BitmapSource?


I have a DrawingBrush with some vector graphics. I want to convert it to BitmapSource as an intermediate step to getting it to Bitmap. What's the (best) way to do this?


Solution

  • public static BitmapSource BitmapSourceFromBrush(Brush drawingBrush, int size = 32, int dpi = 96)
    {
        // RenderTargetBitmap = builds a bitmap rendering of a visual
        var pixelFormat = PixelFormats.Pbgra32;
        RenderTargetBitmap rtb = new RenderTargetBitmap(size, size, dpi, dpi, pixelFormat);
    
        // Drawing visual allows us to compose graphic drawing parts into a visual to render
        var drawingVisual = new DrawingVisual();
        using (DrawingContext context = drawingVisual.RenderOpen())
        {
            // Declaring drawing a rectangle using the input brush to fill up the visual
            context.DrawRectangle(drawingBrush, null, new Rect(0, 0, size, size));
        }
    
        // Actually rendering the bitmap
        rtb.Render(drawingVisual);
        return rtb;
    }