确定点是否在指定区域内

Private Type RECT Left As Long Top As Long Right As Long Bottom As Long End Type Private Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long Private Declare Function PtInRect Lib "user32" (lpRect As RECT, ByVal x As Long, ByVal y As Long) As Long Private Declare Function PtInRegion Lib "gdi32" (ByVal hRgn As Long, ByVal x As Long, ByVal y As Long) As Long Private Declare Function CreateEllipticRgnIndirect Lib "gdi32" (lpRect As RECT) As Long Private Declare Function SetPixelV Lib "gdi32" (ByVal hdc As Long, ByVal x As Long, ByVal y As Long, ByVal crColor As Long) As Long Private Declare Function SetRect Lib "user32" (lpRect As RECT, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long) As Long Private Sub Form_Load() 'KPD-Team 1999 'URL: http://www.allapi.net/ 'E-Mail: KPDTeam@Allapi.net Dim mRGN As Long, R As RECT, x As Long, y As Long 'Set the graphical mode to persistent Me.AutoRedraw = True 'Set the rectangle's values SetRect R, 0, 0, 50, 50 'Create an elliptical region mRGN = CreateEllipticRgnIndirect(R) For x = R.Left To R.Right For y = R.Top To R.Bottom 'If the point is in the region, draw a green pixel If PtInRegion(mRGN, x, y) <> 0 Then 'Draw a green pixel SetPixelV Me.hdc, x, y, vbGreen ElseIf PtInRect(R, x, y) <> 0 Then 'Draw a red pixel SetPixelV Me.hdc, x, y, vbRed End If Next y Next x 'delete our region DeleteObject mRGN End Sub