Thread: Unknown bug

I use MFC to build the interface of a program and I write a new function to re-draw the window style and dialog style (similar to XP style). It's all ok when I run the program at the initial window size, but if I let the window to be max size, the menu bar becomes something wrong, I must double click each menu item, the single click is unavailable.

Code:

void CClassname::DrawTitleBar(CDC *pDC)
{
	if (m_hWnd)
	{
		CBrush Brush(RGB(0,100,255));
		CBrush* pOldBrush = pDC->SelectObject(&Brush);

		CRect rtWnd, rtTitle, rtButtons;
		GetWindowRect(&rtWnd); 
		//Get the position of title
		rtTitle.left = GetSystemMetrics(SM_CXFRAME);
		rtTitle.top = GetSystemMetrics(SM_CYFRAME);
		rtTitle.right = rtWnd.right - rtWnd.left - GetSystemMetrics(SM_CXFRAME);
		rtTitle.bottom = rtTitle.top + GetSystemMetrics(SM_CYSIZE);

		CPoint point;
		//draw the top of the frame
		point.x = rtWnd.Width();
		point.y = GetSystemMetrics(SM_CYSIZE) + GetSystemMetrics(SM_CYFRAME)+20;
		pDC->PatBlt(0, 0, point.x, point.y, PATCOPY);
		//draw the left of the frame
		point.x = GetSystemMetrics(SM_CXFRAME) + 1;
		point.y = rtWnd.Height();
		pDC->PatBlt(0, 0, point.x, point.y, PATCOPY);
		//draw the bottom of the frame
		point.x = rtWnd.Width(); 
		point.y = GetSystemMetrics(SM_CYFRAME) + 1;
		pDC->PatBlt(0, rtWnd.Height()-point.y, point.x, point.y, PATCOPY);
		//draw the right of the frame
		point.x = GetSystemMetrics(SM_CXFRAME) + 1;
		point.y = rtWnd.Height();
		pDC->PatBlt(rtWnd.Width()-point.x, 0, point.x, point.y, PATCOPY);

		
		//Re-draw icon
		m_rtIcon.left = rtWnd.Width() - 135;
		m_rtIcon.top = GetSystemMetrics(SM_CYFRAME);
		m_rtIcon.right = m_rtIcon.left + 32;
		m_rtIcon.bottom = m_rtIcon.top + 32;
		::DrawIconEx(pDC->m_hDC, m_rtIcon.left, m_rtIcon.top, m_hIcon, 
			m_rtIcon.Width(), m_rtIcon.Height(), 0, NULL, DI_NORMAL);
		m_rtIcon.OffsetRect(rtWnd.TopLeft()); 


		//Prepare for the XP sytle button
		CBitmap* pBitmap = new CBitmap;
		CBitmap* pOldBitmap;
		CDC* pDisplayMemDC=new CDC;
		pDisplayMemDC->CreateCompatibleDC(pDC);

		//Re-draw close button
		rtButtons.left = rtTitle.right - 19;
		rtButtons.top = rtTitle.top;
		rtButtons.right = rtButtons.left + 19;
		rtButtons.bottom = rtButtons.top + 19;
		pBitmap->LoadBitmap(IDB_EXIT_NORMAL);
		pOldBitmap=(CBitmap*)pDisplayMemDC->SelectObject(pBitmap);
		pDC->BitBlt(rtButtons.left, rtButtons.top, rtButtons.Width(), rtButtons.Height(), pDisplayMemDC, 0, 0, SRCCOPY);
		pDisplayMemDC->SelectObject(pOldBitmap);
		m_rtButtExit = rtButtons;
		m_rtButtExit.OffsetRect(rtWnd.TopLeft()); 
		pBitmap->DeleteObject();

		//Re-draw restore button
		rtButtons.right = rtButtons.left - 3;
		rtButtons.left = rtButtons.right - 19;
		if (IsZoomed())
			pBitmap->LoadBitmap(IDB_RESTORE_NORMAL);
		else
			pBitmap->LoadBitmap(IDB_MAX_NORMAL);
		pOldBitmap=(CBitmap*)pDisplayMemDC->SelectObject(pBitmap);
		pDC->BitBlt(rtButtons.left, rtButtons.top, rtButtons.Width(), rtButtons.Height(), pDisplayMemDC, 0, 0, SRCCOPY);
		pDisplayMemDC->SelectObject(pOldBitmap);
		m_rtButtMax = rtButtons;
		m_rtButtMax.OffsetRect(rtWnd.TopLeft());
		pBitmap->DeleteObject();

		//Re-draw minisize button
		rtButtons.right = rtButtons.left - 3;
		rtButtons.left = rtButtons.right - 19;
		pBitmap->LoadBitmap(IDB_MIN_NORMAL);
		pOldBitmap=(CBitmap*)pDisplayMemDC->SelectObject(pBitmap);
		pDC->BitBlt(rtButtons.left, rtButtons.top, rtButtons.Width(), rtButtons.Height(), pDisplayMemDC, 0, 0, SRCCOPY);
		pDisplayMemDC->SelectObject(pOldBitmap);
		m_rtButtMin = rtButtons;
		m_rtButtMin.OffsetRect(rtWnd.TopLeft());
		pBitmap->DeleteObject();
	
				
		//Re-draw caption
		int nOldMode = pDC->SetBkMode(TRANSPARENT);
		COLORREF clOldText=pDC->SetTextColor(RGB(255, 255, 255));
		pDC->SelectStockObject(SYSTEM_FIXED_FONT);
		rtTitle.left += 2;
		rtTitle.top += GetSystemMetrics(SM_CYSIZE);
		rtTitle.bottom = rtTitle.top + 30;
		CString m_strTitle;
		GetWindowText(m_strTitle);
		pDC->DrawText(m_strTitle, &rtTitle, DT_LEFT);
		pDC->SetBkMode(nOldMode);
		pDC->SetTextColor(clOldText);

		ReleaseDC(pDisplayMemDC);
		delete pDisplayMemDC;
		delete pBitmap;
	}
}

And you must add a DefWindowProc function and override it

Code:

LRESULT CClassname::DefWindowProc(UINT message, WPARAM wParam, LPARAM lParam) 
{
	LRESULT lrst=CDialog::DefWindowProc(message, wParam, lParam);
	
	if (!::IsWindow(m_hWnd))
		return lrst;
	
	if (message == WM_MOVE||message == WM_PAINT||message==WM_NCPAINT||message==WM_NCACTIVATE ||message == WM_NOTIFY)
	{
		CDC* pWinDC = GetWindowDC();
		if (pWinDC)
			DrawTitleBar(pWinDC);
		ReleaseDC(pWinDC);
	}
	return lrst;
}

PS. The additional declaration in header file:

Code:

public:
	void DrawTitleBar(CDC *pDC);
	CRect m_rtButtExit;	
	CRect m_rtButtMax;	
	CRect m_rtButtMin;		
	CRect m_rtIcon;	
protected:
	HICON m_hIcon;

You can directly use these code in your program for testing