Get a Bitmap from a WPF application window?

Question

The Winforms System.Windows.Forms.Control class has an instance method "DrawToBitmap" which I think is very useful in a variety of circumstances. I'm wondering if there's an equivalent way of getting a System.Drawing.Bitmap from a WPF application?

I realize I could do some P/Invoke stuff to just get the application window, however I don't like this because it doesn't accomodate the 64bit transition very well, and doesn't let me render sub-controls only, as DrawToBitmap does.

Thanks, Richard

Answer 1

Use RenderTargetBitmap as on MSDN

RenderTargetBitmap bitmap = new RenderTargetBitmap(width, height, 96, 96, PixelFormats.Pbgra32);
bitmap.Render(this.YourVisualControlNameGoesHere); 

Answer 2

TFD is spot on. You could also use the less elegant reference example from MSDN:

Dim width As Integer = 128
Dim height As Integer = width
Dim stride As Integer = CType(width / 8, Integer)
Dim pixels(height * stride) As Byte

' Try creating a new image with a custom palette.
Dim colors As New List(Of System.Windows.Media.Color)()
colors.Add(System.Windows.Media.Colors.Red)
colors.Add(System.Windows.Media.Colors.Blue)
colors.Add(System.Windows.Media.Colors.Green)
Dim myPalette As New BitmapPalette(Colors)

' Creates a new empty image with the pre-defined palette
Dim image As BitmapSource = System.Windows.Media.Imaging.BitmapSource.Create(width, height, 96, 96, PixelFormats.Indexed1, myPalette, pixels, stride)
Dim stream As New FileStream("new.bmp", FileMode.Create)
Dim encoder As New BmpBitmapEncoder()
Dim myTextBlock As New TextBlock()
myTextBlock.Text = "Codec Author is: " + encoder.CodecInfo.Author.ToString()
encoder.Frames.Add(BitmapFrame.Create(image))
encoder.Save(stream)