Private Declare Function CreateEllipticRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long '创建一个椭圆，该椭圆与X1，Y1和X2，Y2坐标点确定的矩形内切
Private Declare Function SetWindowRgn Lib "user32" (ByVal hWnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long '改变窗口的区域
Private Sub Form_Load()
Dim mianji As Long
mianji = CreateEllipticRgn(0, 0, 200, 200)
SetWindowRgn Picture1.hWnd, mianji, True
End Sub