Switch persistent views in MDI app

Vincent RICHOMME <richom.v@free.fr>
Fri, 28 Apr 2006 20:47:24 +0200

I am trying to switch between views in a MDI app but I can't.
I found some examples but I am not satisfied with them because they put
it in CDocument. To me it should be in CWinApp or even better in
CmainFrame for a SDI and ChildFrame for a MDI.
Anyway here is the code I use for my MDI app, but the line
pDoc->AddView(pNewView); in the SwitchToView gives me an exception with
the following line from debugger:

if (!AfxIsValidAddress(pOb, pOb->GetRuntimeClass()->m_nObjectSize, FALSE))
__vfptr 0xfeeefeee

I don't understand, all my views are declare DYNAMIC, ...

Does someone has a clean SwitchToView implementation, I am not
interested by code using CDocument like the ones found on CodeGuru or

// Our different Views
enum EViews

BOOL CMyApp::InitInstance()
  // Init all our views
   return TRUE;

void CMyApp::InitViews()
    m_nCurView = 0; // Save index of the currently active view class

    CMDIFrameWnd* pMainWnd = (CMDIFrameWnd*) AfxGetMainWnd();
    CMDIChildWnd* pChild = (CMDIChildWnd*) pMainWnd->MDIGetActive();

    CView* pActiveView = pChild->GetActiveView();

     m_pViews[0] = pActiveView;
     m_pViews[1] = (CView*) new CSmartTokenTesterView;

     CDocument* pCurrentDoc = pChild->GetActiveDocument();
       CRect rect(0, 0, 0, 0); // gets resized later

     // Need to cast pointers to have correct Create functions called
     // CForm2 is CFormView::Create
    for ( int nView=1; nView < N_VIEWS; nView++ )
     m_pViews[nView]->Create(NULL, NULL, AFX_WS_DEFAULT_VIEW, rect,
           pChild, AFX_IDW_PANE_FIRST + 1, NULL);


CView* CMyApp::SwitchToView( UINT nIndex )
     ASSERT( nIndex >=0 && nIndex < N_VIEWS );

     CMDIFrameWnd* pMainWnd = (CMDIFrameWnd*) AfxGetMainWnd();
    CMDIChildWnd* pChild = (CMDIChildWnd*) pMainWnd->MDIGetActive();
    CView* pActiveView = pChild->GetActiveView();
    CDocument* pDoc = pChild->GetActiveDocument();

    if ( !pActiveView ) // No currently active view
         return NULL;

    CView* pNewView = m_pViews[ nIndex ];

     if ( pNewView == pActiveView ) // Already there
         return pActiveView;

    // Set flag so that document will not be deleted when view is dettached.
    BOOL bAutoDelete = m_bAutoDelete;
    m_bAutoDelete = FALSE;
    // Dettach existing view
    // restore flag
    m_bAutoDelete = bAutoDelete;

     m_nCurView = nIndex; // Store the new current view's index

     // exchange view window ID's so RecalcLayout() works
    UINT temp = ::GetWindowLong(pActiveView->m_hWnd, GWL_ID);
     ::SetWindowLong(pActiveView->m_hWnd, GWL_ID,
     ::GetWindowLong(pNewView->m_hWnd, GWL_ID));
     ::SetWindowLong(pNewView->m_hWnd, GWL_ID, temp);

     // Display and update the new current view - hide the old one

    //((CMDIFrameWnd*) m_pMainWnd)->SetActiveView(pNewView);
     //((CMDIFrameWnd*) m_pMainWnd)->RecalcLayout();

    // Attach new view


     return pActiveView;

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