Draw drop shadow

Question

I want to add a drop shadow to an image file. What's the best way to do that? I thought about creating a WPF Image control and adding a bitmap effect.. But how can I save the result to a file?

Thanks, Eric

Answer 1

You can use RenderTargetBitmap and an Encoder to do this. Encoder can be Png,Jpeg etc.. Below code imgControl represents your Image control. But since it is a bitmap effect you might need to put this Image inside a grid and give proper margin equivalent to the dropshadow and then instead of imgControl use the grid in the below code.

double Height = imgControl.ActualHeight;
double Width = imgControl.ActualWidth;

RenderTargetBitmap bmp = new RenderTargetBitmap((int)Width, (int)Height, 
                                                96, 96, PixelFormats.Pbgra32);
bmp.Render(imgControl);

BitmapEncoder encoder = new JpegBitmapEncoder();

encoder.Frames.Add(BitmapFrame.Create(bmp));

using (Stream stream = File.Create("Yourfile.jpeg"))
{
    encoder.Save(stream);
}