win32APIのインポート

<System.Runtime.InteropServices.DllImport("gdi32.dll")> _
Private Shared Function BitBlt(ByVal hdcDest As IntPtr, _
    ByVal nXDest As Integer, ByVal nYDest As Integer, _
    ByVal nWidth As Integer, ByVal nHeight As Integer, _
    ByVal hdcSrc As IntPtr, _
    ByVal nXSrc As Integer, ByVal nYSrc As Integer, _
    ByVal dwRop As Integer) As Boolean
End Function