New Post: Invalidate not present in WPF

        wbmp = BitmapFactory.New(300, 300);
        IMG1.Source = wbmp;
        BitmapContext bmpc = wbmp.GetBitmapContext();

        // Clear the WriteableBitmap with white color
        wbmp.Clear(Colors.Red);

        wbmp.DrawLine(0, 0, 1000, 1000, Colors.Black);