请教：为什么下面程序运行后图片框3会出现两张图片？

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 Const SRCCOPY = &HCC0020 ' (DWORD) dest = source

Private Sub command1_Click()
Picture3.ScaleMode = 3
Picture1.ScaleMode = 3
Picture2.ScaleMode = 3
  BitBlt Picture2.hDC, 0, 0, Picture1.ScaleWidth / 2, Picture1.ScaleHeight / 2, Picture1.hDC, 0, 0, &HCC0020
  BitBlt Picture3.hDC, 120 / 15, 120 / 15, Picture1.Width, Picture1.Height, Picture1.hDC, 0, 0, &HCC0020
  End Sub

因为你最后一句是绘制 Picture3 呀，如果 Picture3 本身有图片，再绘制一次不就这样了