public static void fSetBackground(System.Windows.Forms.Control control, Bitmap bitmap) { // Set our control's size to be the same as the bitmap control.Width = bitmap.Width; control.Height = bitmap.Height; if (bitmap.PixelFormat != PixelFormat.Format32bppArgb) { throw new ApplicationException("must be 32 bits per pixel"); } IntPtr hBitmap = IntPtr.Zero; IntPtr oldBitmap = IntPtr.Zero; IntPtr screenDc = Win32.GetDC(IntPtr.Zero); IntPtr memDc = Win32.CreateCompatibleDC(screenDc); try { hBitmap = bitmap.GetHbitmap(Color.FromArgb(0)); oldBitmap = Win32.SelectObject(memDc, hBitmap); Win32.Size size = new Win32.Size(bitmap.Width, bitmap.Height); Win32.Point pointSource = new Win32.Point(0, 0); Win32.Point topPos = new Win32.Point(control.Left, control.Top); Win32.BLENDFUNCTION blend = new Win32.BLENDFUNCTION(); blend.BlendOp = 0; blend.BlendFlags = 0; blend.SourceConstantAlpha = byte.MaxValue; blend.AlphaFormat = 1; Win32.UpdateLayeredWindow(control.Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, 2); } catch (Exception ex) { throw ex; } finally { Win32.ReleaseDC(IntPtr.Zero, screenDc); if (hBitmap != IntPtr.Zero) { Win32.SelectObject(memDc, oldBitmap); Win32.DeleteObject(hBitmap); } Win32.DeleteDC(memDc); } }