小吳 VBQA 程式設計討論

我初用BitBlt WinApi。
程式碼如下:
Private Declare Sub 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)
Private Sub Command1_Click()
BitBlt Picture2.hDC , 0, 0, 100, 100, Picture1.hDC, 0, 0, &HCC0020
End Sub
我已直接從Sample中直抄，但為何不能將Picture1的image copy到Picture2中?