Problem using OCX in Mixed MFC & Managed App

RE: Problem using OCX in Mixed MFC & Managed App

Hi Werner,
[color=blue]
>If I comment out the OleInitialize in InitInstance, then the Message[/color]
disappeares and all seems
to be OK until a MFC-based dialog which contains an OCX is created.
At this point an assertion occurs in occmgr.cpp
COccManager::Cr eateDlgControls at (Line 410)
"
COleControlSite OrWnd *pTemp =new
COleControlSite OrWnd(::GetDlgI tem(pWndParent->GetSafeHwnd( ),
pOccDlgInfo->m_pItemInfo[i].nId),pOccDlgIn fo->m_pItemInfo[i].bAutoRadioButt o
n);
ASSERT(pTemp->m_hWnd);
"[color=blue]
>[/color]

The OleInitialize could not be commented out in InitInstance,an d it is true
that your MFC ocx controls should be loaded in a STA thread.

[color=blue]
>I have a VC7 App consisting of "old" MFC-Source and new Manged Source that[/color]
uses an OCX
in one of its MFC-based dialogs.
...
I guess, that some CLR - related Code has done this (because the same App
without /CLR-Option
and managed Sources does not have this problem.[color=blue]
>[/color]

Which project type of your VC7 application?
Based on your description, it appears that its main thread is a MTA thread
when complied as managed code, if so, how about call your MFC dialog(with
ocx control) in a child thread which resides in a STA?


Thanks!

Best regards,

Gary Chang
Microsoft Online Partner Support
Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------

RE: Problem using OCX in Mixed MFC & Managed App

Hi Gary

thank you very much for your response
Here are the answers to your questions (and my new
questions resulting from your answers ..
[color=blue]
>Which project type of your VC7 application?[/color]

It is an MFC-EXE-App project, created with VC6 (dsw/dsp) and then automatically upgrade
by VS .NET 2003 to VC7 (sln/vcproj
[color=blue]
>Based on your description, it appears that its main thread is a MTA thread[/color]
when complied as managed cod

My MFC source itself is not multithreaded; it never starts any child threads an
it never calls CoInitializeEx with COINIT_MULTITHR EADED mode
so I don't know why the main thread is a MTA thread
does "/CLR" make it a MTA thread ?
or the usage of .NET Framework classes

Is it possible to make the main thread an STA thread again (as it was before I change
the project to "/CLR" mode and used .NET Framework classes) ?
If yes, how
[color=blue]
> if so, how about call your MFC dialog(with[/color]
ocx control) in a child thread which resides in a STA

how can this be done that my (complete) MFC-App-Source would ru
in a child thread which resides in a STA

Thanks in advance for your answers

Werne

RE: Problem using OCX in Mixed MFC & Managed App

Hi Werner,

Thanks for the quickly reply!

After reviewing your messages carefully, now I can confirm the problem is a
known issue to the VS.NET 2003, you can find the resolution in the
following KB:

BUG: "HRESULT - 0x80010106" Error When You Run a Managed C++ Application


However, for a MFC application, the managed entry point function should be
modified as:
//in Appname.cpp
...
#define _WIN32_WINNT 0x501 //for Windows2000, please use 0x0500
#include <objbase.h>
#include <stdio.h>

#using <mscorlib.dll >
using namespace System;

extern "C" void WinMainCRTStart up();

[System::STAThre ad]
int mymain() //the new entry point
{
//Initialize COM
HRESULT hr = CoInitialize(0) ;

//Initialize the CRT
WinMainCRTStart up();
//uninit
CoUninitialize( );
return 0;
}
...

[color=blue]
>so I don't know why the main thread is a MTA thread;
>does "/CLR" make it a MTA thread ?
>or the usage of .NET Framework classes ?[/color]
Please refer to the above KB.
[color=blue]
>Is it possible to make the main thread an STA thread again (as it was[/color]
before I changed[color=blue]
>the project to "/CLR" mode and used .NET Framework classes)?[/color]
We don't recommend make the main thread an STA thread again, you can make
it an STA thread from the beginning, please check the KB.
[color=blue]
>how can this be done that my (complete) MFC-App-Source would run in a[/color]
child thread which resides in a STA?[color=blue]
>[/color]
For the reason that your project is a MFC application project upgraded from
the VC6, you needn't take such an approach.


Thanks!

Best regards,

Gary Chang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.
--------------------

RE: Problem using OCX in Mixed MFC &amp; Managed App

Hi Gary

the code snippet from your last post inserted in my <Appname>.cpp solved the problem

Thank you very much

(I had searched the KB for this problem, but did'nt find KB 824480, because I searche
for RPC_E_CHANGED_M ODE and AfxOleInit

Best regards

Werne