is there anyone familiar with COM? I met problem when changed project from MFC to Qt

[opengpu]

@hskoglund that DLL with COM is not Qt program...

[mrjj]

@opengpu
Hi
then use std::cout to show the HRESULT.
It can give hints about why its not loading,.

What im a bit puzzled about if that is the same DLL used in the MFC app, and you did not change
the actual DLL code. why should it then stop working?

[opengpu]

the DLL is the same...
and i wiil log out the errorcode

[opengpu]

anyone familiar ?

[mrjj]

@opengpu
did you get HRESULT hr out ?

[opengpu]

@mrjj HRESULT = -2147417850

[mrjj]

@opengpu
ok. super. Hopefully mr hskoglund can get something out of that.

[aha_1980]

https://en.m.wikipedia.org/wiki/HRESULT describes tools to decode HRESULTs

[Christian Ehrlicher]

@opengpu said in anyone familiar with COM? i met problem when changed project from MFC to Qt:

-2147417850

= 0x80010106

https://stackoverflow.com/questions/11708497/com-library-initialization-failed-with-code-0x80010106-in-c-sharp

"This is a bug in the DLL you are using. A DLL should never call CoInitializeEx() on a thread that it didn't create. "

[hskoglund]

Hi, what happens to your .DLL if you skip (comment out) the call to CoInitializeEx()?

[opengpu]

0x80010106

[opengpu]

This post is deleted!

[opengpu]

#include "stdafx.h"

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
					 )
{
	switch (ul_reason_for_call)
	{
	case DLL_PROCESS_ATTACH:
	case DLL_THREAD_ATTACH:
	case DLL_THREAD_DETACH:
	case DLL_PROCESS_DETACH:
		break;
	}
	return TRUE;
}

[opengpu]

APIImp::APIImp()
{
	//if(!SUCCEEDED(CoInitialize(NULL)))
	HRESULT ret = CoInitializeEx(NULL, COINIT_MULTITHREADED);
	if(!SUCCEEDED(ret))
	{
		//return;
	}

	initialize();
}

[opengpu]

@hskoglund why you asked this question?
i didnot return when failed to CoInitializeEx(NULL, COINIT_MULTITHREADED);
it seems worked...

[opengpu]

APIImp::APIImp()
{
	//if(!SUCCEEDED(CoInitialize(NULL)))
	HRESULT ret = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
	if(!SUCCEEDED(ret))
	{
		return;
	}

	initialize();
}

i use COINIT_APARTMENTTHREADED instead of COINIT_MULTITHREADED, and this works fine for me.