PRB: Print Preview Displays in MDI Child Frame

• Microsoft Visual C++, 32-bit Editions, versions 4.2b, 5.0

SYMPTOMS

When you display print preview for an MDI application, the preview view is displayed in the MDI child window rather than the MDI frame window.

CAUSE

The MFC sources were changed to fix a bug when mixing Active X documents and print preview.

RESOLUTION

Rebuild the MFC libraries and statically link to it.

STATUS

This behavior is by design.

MORE INFORMATION

When MFC's print preview is invoked, it searches for the frame window of the current view using GetParentFrame to display the preview view. This is done in CView::DoPrintPreview. The code below reflects some of the changes that DoPrintPreview went through between Visual C++ 4.2 and 5.0.

   // VC 4.2
   BOOL CView::DoPrintPreview(UINT nIDResource, CView* pPrintView,
      CRuntimeClass* pPreviewViewClass, CPrintPreviewState* pState)
   {
      ...
      CFrameWnd* pParent = (CFrameWnd*)AfxGetThread()->m_pMainWnd;
      ASSERT_VALID(pParent);
      ASSERT_KINDOF(CFrameWnd, pParent);
      ...
   }

   // VC 5.0
   BOOL CView::DoPrintPreview(UINT nIDResource, CView* pPrintView,
      CRuntimeClass* pPreviewViewClass, CPrintPreviewState* pState)
   {
      ...
      CFrameWnd* pParent;
      CWnd* pNaturalParent = pPrintView->GetParentFrame();
      pParent = DYNAMIC_DOWNCAST(CFrameWnd, pNaturalParent);
      if (pParent == NULL || pParent->IsIconic())
         pParent = (CFrameWnd*)AfxGetThread()->m_pMainWnd;
      ...
   }

To get back the old behavior you have to modify the MFC sources and rebuild the MFC libraries. It is not possible to override DoPrintPreview in your CView derived class since it requires the use of protected members of friend classes.

Rebuilding the MFC libraries is not supported.