应用API函数在用户窗体中画圆

Private Declare Function GetDC Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Private Declare Function CreatePen Lib "gdi32" (ByVal nPenStyle As Long, ByVal nWidth As Long, ByVal crColor As Long) As Long
Private Declare Function CreateSolidBrush Lib "gdi32" (ByVal crColor As Long) As Long                    '
Private Declare Function SelectObject Lib "gdi32" (ByVal hdc As Long, ByVal hObject As Long) As Long
Private Declare Function Ellipse Lib "gdi32" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long

Sub MyCircle(MyObject As Object, pX As Long, pY As Long, pR As Long, lcColor As Long, lcFill As Long)
'MyObject 指定圆所在的对象
'
'pX 圆心在对象体上X轴
'
'pY 圆心在对象体上Y轴
'
'pR 圆的半径
'
'lcColor 圆的轮廓颜色
'
'lcFill 圆的填充色

Dim hdc As Long, hpen As Long, hcolor As Long
hdc = GetDC(FindWindow(vbNullString, MyObject.Caption))
hpen = CreatePen(0, 1, lcColor)
hcolor = CreateSolidBrush(lcFill)
SelectObject hdc, hpen
SelectObject hdc, hcolor
Ellipse hdc, pX - pR, pY - pR, pX + pR, pY + pR
DeleteObject hpen
DeleteObject hcolor
End Sub
'

Private Sub UserForm_Click()
MyCircle UserForm1, 100, 100, 50, vbRed, vbBlue
End Sub