Re: using Document object from CFrameWnd

From:

=?Utf-8?B?bmV4b2xpdGU=?= <nexolite@discussions.microsoft.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Sun, 25 Jan 2009 08:46:04 -0800

Message-ID:

<24B6C343-27D5-4AA5-A9F2-EF3776B89F86@microsoft.com>

Now one more amazing thing to see!
I created a simple SDI app to test all this ,in that I create two splitters
if(!m_wndSplitter.CreateStatic(this,1,2)||
    !m_wndSplitter.CreateView(0,0,RUNTIME_CLASS(CMyFrame),CSize(0,0),pContext)||
    !m_wndSplitter.CreateView(0,1,RUNTIME_CLASS(CMypView),CSize(0,0),pContext))
    return FALSE;

In CMyFrame I am not able to get the document pointer as before and
in CMyView I am able to get it using GetDocument() BUT..
If try to use the same thing that I used in CMyFrame to get the pointer i.e:
CFrameWnd* pFrame=(CFrameWnd*)AfxGetMainWnd();
    CSDIExpDoc* pDoc=(CSDIExpDoc*)pFrame->GetActiveDocument();

I am NOT able to get the pointer this way!
and also have anybody used a CFrameWnd in a splitter window(as a view) and
got the document pointer??

"Joseph M. Newcomer" wrote:

See below...
On Sun, 25 Jan 2009 06:03:01 -0800, nexolite <nexolite@discussions.microsoft.com> wrote:

(a) where in your code are you doing this?

*******************************
I am doing this in a class derived from CFrameWnd in OnLButtonDown()
which is used as a view in one of the split window.
********************************

(b) what value do you get for pDOC or pFrame? NULL? 0xDFDFDFDF? 0xFEEEFEEE?

***************************************************
pDoc=0x00000000
pFrame=0x00ce6148

****
At this point you can stop. Nothing matters. pDoc is NULL. You have to figure out why
pDOC is NULL. Note that you must always check values and not proceed to use them, for
example

pDoc = ....;
ASSERT(pDoc != NULL);
if(pDoc == NULL)
return;

or something like that. Blindly going off and using a value without having tested it
leads to the situation you are in.

Then you have to ask, why is the document NULL? Go back and look at how you created your
view, and how you attached it to the document.
****

***************************************************

**************************************
debugger points to pDoc->store=0; or whenever I try to access any member(in
same OnLButtonDown())

(d) what is the call stack back to your code?

********************************* -->App.exe!CAbView::OnLButtonDown(unsigned int flag=1, CPoint point={...}) Line 202 + 0x9 bytes C++

    App.exe!CWnd::OnWndMsg(unsigned int message=513, unsigned int wParam=1,
long lParam=13697493, long * pResult=0x0012fcbc) Line 2169 C++

    App.exe!CWnd::WindowProc(unsigned int message=513, unsigned int wParam=1,
long lParam=13697493) Line 1741 + 0x20 bytes C++

    App.exe!AfxCallWndProc(CWnd * pWnd=0x00ce6e08, HWND__ * hWnd=0x0004094c,
unsigned int nMsg=513, unsigned int wParam=1, long lParam=13697493) Line

    240 + 0x1c bytes C++

    App.exe!AfxWndProc(HWND__ * hWnd=0x0004094c, unsigned int nMsg=513,
unsigned int wParam=1, long lParam=13697493) Line 389 C++
    user32.dll!77d48709()

    [Frames below may be incorrect and/or missing, no symbols loaded for
user32.dll]
    user32.dll!77d487eb()
    user32.dll!77d70494()
    user32.dll!77d489a5()
    user32.dll!77d70494()
    user32.dll!77d4bccc()

    App.exe!AfxInternalPumpMessage() Line 183 C++

    App.exe!CWinThread::PumpMessage() Line 896 C++

    App.exe!CWinThread::Run() Line 625 + 0xd bytes C++

    App.exe!CWinApp::Run() Line 894 C++

    App.exe!AfxWinMain(HINSTANCE__ * hInstance=0x00400000, HINSTANCE__ *
hPrevInstance=0x00000000, char * lpCmdLine=0x00151f41, int nCmdShow=1) Line

    47 + 0xd bytes C++

    App.exe!WinMain(HINSTANCE__ * hInstance=0x00400000, HINSTANCE__ *
hPrevInstance=0x00000000, char * lpCmdLine=0x00151f41, int nCmdShow=1) Line
33

    C++

    App.exe!__tmainCRTStartup() Line 324 + 0x35 bytes C

    App.exe!WinMainCRTStartup() Line 196 C

    kernel32.dll!7c816d4f()

    kernel32.dll!7c8399f3()

    App.exe!COleServerDoc::XOleObject::SetHostNames(const wchar_t *
lpszContainerApp=0x00380078, const wchar_t * lpszContainerObj=0x00220036)
Line

    2068 + 0x2d bytes C++
*****************************************************

Without knowing (a) and (b) there is no good way to answer the question. (c) and (d) help
isolate what is going on.

****
Since you've established the document is NULL, you have to follow how that came about. You
would have to show how you created the splitter views. I won't see any messages until
next Sunday; I'm gone from an hour from now until late Saturday night.
joe
*****

joe

On Fri, 23 Jan 2009 21:36:01 -0800, nexolite <nexolite@discussions.microsoft.com> wrote:

But NONE is working,
wether I do:

1> CMyDoc* pDoc=(CMyDoc*) GetActiveDocument();

OR..

2> CFramewnd* pFrame=(CFrameWnd*)AfxGetMainWnd();
CMyDoc* pDoc=(CMyDoc*) pFrame->GetActiveDocument();

OR...

3>CMyFrame* pFrame=(CMyFrame*)AfxGetMainWnd();
CMyDoc* pDoc=(CMyDoc*) pFrame->GetActiveDocument();

while using any of these I am getting Access Violation.
what I should do?

"Giovanni Dicanio" wrote:

"David Wilkinson" <no-reply@effisols.com> ha scritto nel messaggio
news:eLr2%23KXfJHA.5496@TK2MSFTNGP02.phx.gbl...

If the CFrameWnd is just "used as a view", will it be hooked up correctly
to MFC so that GetActiveDocument() will work? I wouldn't think so.

I would have thought you would need to do something like

CFrameWnd* pFrame = (CFrameWnd*)AfxGetMainWnd();
CMyDocument* pDoc = (CMyDocument*)pFrame->GetActiveDocument();

or maybe better pass a CMyDocument* pointer to the new CFrameWnd and store
it in a member variable,

David: I did not try that with a real test with the C++ compiler, so I trust
much more what you think considering your experience, that what I suppose
without a real test.

Thanks,
Giovanni

Joseph M. Newcomer [MVP]
email: newcomer@flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm