在一个Form中定义两个按钮,cmd1和command2,书写以下代码:
Private Sub cmd1_Click()
MsgBox "ok"
End Sub
Private Sub Command2_Click()
Dim crgn As Long
Dim ret As Long
crgn = CreateEllipticRgn(5, 5, cmd1.Width - 5, cmd1.Height - 5)
ret = SetWindowRgn(cmd1.hwnd, crgn, True)
cmd1.Caption = "ok"
cmd1.Visible = True
End Sub
API函数:
Public Declare Function SetWindowRgn Lib "user32" (ByVal hwnd As Long, ByVal hRgn As Long, ByVal bRedraw As Boolean) As Long
Public Declare Function CreateEllipticRgn Lib "gdi32" (ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long