Changes in Print Preview behavior since Visual C++ 4.2

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++ versions 4.2 and 6.0:

Visual C++ 4.2

In Visual C++ 4.2, Print Previews always appear in the MDI frame window. This was the original behavior.

// 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);
				

Visual C++ 4.2b

In Visual C++ 4.2b, Print Preview was moved to the MDI child frame to support Active Documents. However, it appears in the MDI frame window only when the parent of the view is not a CFrameWnd-derived object (such as a splitter window). This inconsistency was considered a bug and was fixed in Visual C++ 5.0.

// VC 4.2b
BOOL CView::DoPrintPreview(UINT nIDResource, CView* pPrintView,
    CRuntimeClass* pPreviewViewClass, CPrintPreviewState* pState)
{
    ...
    CFrameWnd* pParent;
    CWnd* pNaturalParent = pPrintView->GetParent();
    pParent = DYNAMIC_DOWNCAST(CFrameWnd, pNaturalParent);
    if (pParent == NULL)
        pParent = (CFrameWnd*)AfxGetThread()->m_pMainWnd;
				

Visual C++ 5.0

In VC 5.0, Print Preview always appears within the MDI child window. (This was the intended "feature" in Visual C++ 4.2b.)

// 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;
				

Visual C++ 6.0

For Visual C++ 6.0, Microsoft decided that Print Preview belongs in the MDI main frame window, so its behavior was changed back. (The Visual C++ 5.0 "feature" was considered a bug.)

BOOL CView::DoPrintPreview(UINT nIDResource, CView* pPrintView,
    CRuntimeClass* pPreviewViewClass, CPrintPreviewState* pState)
{
    ...
    CFrameWnd* pParent = STATIC_DOWNCAST(CFrameWnd, AfxGetMainWnd());
    ASSERT_VALID(pParent);
				

To change the behavior of Print Preview in any of the versions, you have to modify the MFC sources and rebuild the MFC libraries. It is not possible to override DoPrintPreview in your CView-derived class because it requires the use of protected members of friend classes.

The best design approach is to write your application using the behavior where Print Preview appears within the MDI main frame window. This is the current behavior of MFC.