Cant Invalidate bitmap

Oct 31, 2012 at 8:13 PM
The code below will not compile VS is claiming that  
Invalidate() is not a valid function.  I am using WPF in .NET 4.0 with the 
WriteableBitmapEx.Wpf  found in the (seems the same as the

    var writeableBmp = BitmapFactory.New(512, 512);
    ImageControl.Source = writeableBmp;
    writeableBmp.FillTriangle(10, 5, 20, 40, 30, 10, Colors.Black);

Any help is appreciated.

Also is there anywhere to download a functioning code sample for XAML?