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Painting Issues In MFC MDI applications on Windows 7 Boxes

You may see painting issues with MFC MDI Office Style Applications when resizing or moving the window around as shown below

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This bug is caused by different values returned by GetSystemMetrics() under VS 2010 and VS 2012 (the issue was discussed here: https://connect.microsoft.com/VisualStudio/feedback/details/753224/regression-getsystemmetrics-delivers-different-values .

If you are hit by the issue, it can be resolved in application by adding WM_NCCALCSIZE message handlers to CMainFrame and CChildFrame classes:

void CMainFrame::OnNcCalcSize(BOOL bCalcValidRects, NCCALCSIZE_PARAMS* lpncsp)

{

CMDIFrameWndEx::OnNcCalcSize(bCalcValidRects, lpncsp);

if (!afxGlobalData.IsDwmCompositionEnabled() && CMFCVisualManager::GetInstance()->IsOwnerDrawCaption())

       {

int cxPaddedBorder = GetSystemMetrics(SM_CXPADDEDBORDER);

if (cxPaddedBorder != 0)

              {

lpncsp->rgrc[0].top -= cxPaddedBorder;

lpncsp->rgrc[0].bottom += cxPaddedBorder;

              }

       }

}

void CChildFrame::OnNcCalcSize(BOOL bCalcValidRects, NCCALCSIZE_PARAMS* lpncsp)

{

CMDIChildWndEx::OnNcCalcSize(bCalcValidRects, lpncsp);

if (!afxGlobalData.IsDwmCompositionEnabled() && CMFCVisualManager::GetInstance()->IsOwnerDrawCaption())

       {

int cxPaddedBorder = GetSystemMetrics(SM_CXPADDEDBORDER);

if (cxPaddedBorder != 0)

              {

lpncsp->rgrc[0].top -= cxPaddedBorder;

              }

       }

}