'API声明
Private Declare Function BitBlt Lib "gdi32"   ( ByVal hDestDC As Long,ByVal x As Long,ByVal y As Long,ByVal nWidth As Long,ByVal nHeight As Long,ByVal hSrcDC As Long,ByVal xSrc As Long,ByVal ySrc As Long,ByVal dwRop As Long )   As Long

Private Sub Command1_Click (   )  
      BitBlt 目标图.hDC,( 目标图.Width / 2 - 掩码图.Width / 2 )   / 15,掩码图.Width / 15,掩码图.Height / 15,掩码图.hDC,vbSrcAnd
      BitBlt 目标图.hDC,源图.hDC,vbSrcInvert
End Sub