public static int AlphaBlend( 
   int sa,
   int sr,
   int sg,
   int sb,
   int destPixel
)

Parameters

sa

sr

sg

sb

destPixel

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

WriteableBitmapExtensions Class
WriteableBitmapExtensions Members