Replacing views in MDI.

Svetlana Guljajeva -- svetlana@assert.ee
Friday, November 08, 1996

Environment: VC++ 4.2-flat, Win 95

Hello!

I have an MDI application,and in every child frame I want to change
views(replace).

 I got an assertion fault in CDataExcange::PrepareCtrl function:

	HWND hWndCtrl;
	m_pDlgWnd->GetDlgItem(nIDC, &hWndCtrl);
	if (hWndCtrl == NULL)
	{
		TRACE1(...);
		ASSERT(FALSE);
		AfxThrowNotSupportedException();
	}
	m_hWndLastControl = hWndCtrl;

This was called from DoDataExchange()<--UpdateData(0)<--OnInitialUpdate()

After GetDlgItem my hWndCtrl is NULL.Actually all the member valiables'
hWndCtrl are NULL.My question is : why??
here is a function where I change views:

BOOL CChildFrame::ReplaceView(CRuntimeClass * pViewClass)
{
	CCreateContext context;
	CView * pCurrentView;
	
	if((pCurrentView = GetActiveView()) == NULL)
		return FALSE;

	CDocument * pDoc = pCurrentView->GetDocument();
	BOOL bAutoDelete = pDoc->m_bAutoDelete;
	pDoc->m_bAutoDelete = FALSE;

	pCurrentView->DestroyWindow();

	pDoc->m_bAutoDelete = bAutoDelete;

	context.m_pNewViewClass = pViewClass;
	context.m_pCurrentDoc = pDoc;
	context.m_pNewDocTemplate = NULL;
	context.m_pLastView = NULL;
	context.m_pCurrentFrame = this;
	
	CView * pNewView = (CView *) pViewClass->CreateObject();

	if(pNewView == NULL)
	{
		TRACE1("Warning:Dynamic create of view type %Fs failed \n",
				pViewClass->m_lpszClassName);
		return FALSE;
	}

	if(!pNewView->Create(NULL,NULL,AFX_WS_DEFAULT_VIEW,CRect(0,0,0,0),this,AFX_
IDW_PANE_FIRST,&context))
	{
		TRACE0("Warning:failed to create view for frame\n");
		return FALSE;
	}

	pNewView->SendMessage(WM_INITIALUPDATE,0,0);

	RecalcLayout();

	pNewView->UpdateWindow();

	SetActiveView(pNewView);

	return TRUE;
}

What else should I call to tie my member variables correctly with their
actual controls??

Thanks in advance,
        Svetlana
-----------------------------------------
**svetlana@assert.ee**
//**Assert Ltd.**\\
//****Tallinn****\\
//****Estonia****\\

---

Jim Lawson Williams -- jimlw@mail.ccur.com.au
Sunday, November 10, 1996

G'day!
At 11:22 AM 08-11-96 +0200, you wrote:
>Environment: VC++ 4.2-flat, Win 95
>
      
>BOOL CChildFrame::ReplaceView(CRuntimeClass * pViewClass)
>{
      
>	context.m_pNewDocTemplate = NULL;
                                    ^^^^
I don't know the answer, but this looks suspicious....

Regards,
Jim LW

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