Re: AfxGetApp() returns NULL

From:

"Ajay Kalra" <ajaykalra@yahoo.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 7 Dec 2007 22:37:23 -0500

Message-ID:

<31E74A62-0932-4E13-8088-FE420090EA20@microsoft.com>

"LogicMan" <garybell.home@gmail.com> wrote in message
news:5eb6526f-f6d4-4a21-bc48-9340d2b2dc10@w40g2000hsb.googlegroups.com...

Thanks again for your help. I'm not sure you mix versions. Would
it happen by linking against LIB files from a previous version?

Use DEPENDS.exe and see if you have multiple versions of MFC linked in your
module. I suspect this to be the case. Make sure you rebuild all the
projects when you build in VS2005. This also means all your module are
either Debug or Release, include COM servers.

---
Ajay

On Dec 7, 7:48 pm, "Ajay Kalra" <ajayka...@yahoo.com> wrote:

Also, Are you by any chance mixing various versions of MFC. That could
happen if you havent migrated all projects to the newer version(thats
likely
if this is happening in an EXE and it worked in VS2003).

---
Ajay

"Ajay Kalra" <ajayka...@yahoo.com> wrote in message

news:9B30B7F4-9A15-4109-A6BD-55BED866AC5E@microsoft.com...

This would happen in a MFC Regular DLL if you havent use
AFX_MANAGE_STATE
properly. Is this in a Regular DLL or in a Exe?

---
Ajay

"LogicMan" <garybell.h...@gmail.com> wrote in message
news:953f6a25-a0be-4803-8cdf-5e36b0cb4235@b15g2000hsa.googlegroups.com...

Hi,

While I've been programming for a number of years I'm fairly new to
MFC (and C++ for that matter). I have inherited a rather large MFC
app that had been done in VS2003. I recently moved it to VS2005.
While I was able to make it compile with much troubleI immediately ran
into major problems running the application. They manifested as
access violations and were all centered around calls to AfxGetApp() to
access member variables of the main application object. It's not
always the same place in the application, but it's always the same
sequence. AfxGetApp() ends up calling the routine below. When the
if(pState->m_pModuleState != NULL) is true then it ends up returning a
NULL value. When it falls through to use the
_afxBaseModuleTate.GetData() then all is well. This is all in the
main app, not a DLL, although there are quite a few DLLs that get
referenced (as in process COM objects).

I'm a bit over my head on this. I've been able to make most problem
go away by replacing any AfxGetApp()-> references with thisApp.
references. but obviously there's stuff going on that Is there some
direction I can take to help solve this? Is there something
inherently different in VS2005 than VS2003 that I should be aware of
as it pretains to how state is stored, etc?

Any direction would be greatly appreciated. Thanks!!

AFX_MODULE_STATE* AFXAPI AfxGetModuleState()
{
_AFX_THREAD_STATE* pState = _afxThreadState;
ENSURE(pState);
AFX_MODULE_STATE* pResult;
if (pState->m_pModuleState != NULL)
{
// thread state's module state serves as override
pResult = pState->m_pModuleState;
}
else
{
// otherwise, use global app state
pResult = _afxBaseModuleState.GetData();
}
ENSURE(pResult != NULL);
return pResult;
}