PaintDone event |
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Remarks Occurs immediately after the completion of the control graphical rendering. Catching this event will allow to make further rendering on the control surface through the hDC parameter. For further details about custom graphic rendering see the How to perform custom graphic rendering over the control surface section.
Syntax Visual Basic BtnEnh1_PaintDone (ByVal hDC As Long)
Visual C++ void PaintDone (long hDC);
It's important to note that each of the available controls can have a different drawing function.
Let's see a sample that demonstrates how to paint a red circle over the button surface:
Visual Basic example Inside a BAS module, add the following declarations that will allow accessing the Windows GDI primitives Public Declare Function SelectObject Lib "gdi32" (ByVal hDC As Long, ByVal hObject As Long) As Long Public 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 Public Declare Function DeleteObject Lib "gdi32" (ByVal hObject&) As Long Public Declare Function CreateSolidBrush Lib "gdi32" (ByVal crColor As Long) As Long Inside the same BAS module add the following subroutine that will perform our custom rendering Sub MyPaintFunction(ByVal hDC As Long) Dim brushColor As Long Dim brushOld As Long brushColor = CreateSolidBrush(RGB(255, 0, 0)) brushOld = SelectObject(hDC, brushColor) Ellipse hDC, 10, 10, 50, 50 SelectObject hDC, brushOld DeleteObject brushColor End Sub Inside the form code, catch the PaintDone event for the control BtnEnh1 and call the MyPaintFunction subroutine declared above Private Sub BtnEnh1_PaintDone(ByVal hDC As Long) MyPaintFunction hDC End Sub
Visual C++ example Supposing that we have a dialog box with a button identified by IDC_BTNENHCTRL1, let's add the management function for the PaintDone event
BEGIN_EVENTSINK_MAP(CMyDialog, CDialog) //{{AFX_EVENTSINK_MAP(CMyDialog) ON_EVENT(CMyDialog, IDC_BTNENHCTRL1, 11 /* PaintDone */, OnPaintDoneBtnenhctrl1, VTS_I4) //}}AFX_EVENTSINK_MAP END_EVENTSINK_MAP() The OnPaintDoneBtnenhctrl1management function will look like this: void CMyDialog::OnPaintDoneBtnenhctrl1(long hDC) { HBRUSH brushColor = ::CreateSolidBrush (RGB (255,0,0)); HBRUSH brushOld = (HBRUSH) ::SelectObject ((HDC) hDC, brushColor); ::Ellipse((HDC) hDC, 10, 10, 50, 50); ::SelectObject ((HDC) hDC, brushOld); ::DeleteObject (brushColor); }
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