Re: beginner: assertion error on class export from dll

Hi everybody...

im stuck and after crawling thru usenet for days and still beeing
unable to solve my problem, i post it.

what i want is: i want a dll export a class.
what i've read and tried to understand is...

http://www.codeproject.com/dll/dlltips.asp?df=100&forumid=855&exp=0&select=615608
what i did is listed below.
what i got is...

-------------------------------------------------
| Debug Assertion Failed! |
| |
| Program: (path to my prog) |
| File: dbgheap.c |
| Line: 1011 |
| |
| Expression: _CrtIsValidHeapPointer(pUserData) |
-------------------------------------------------

what i'd really apreciate is some enlightenment what im doing wrong.

currently im doing it wrong with microsoft vc++ 6; here's the code:

##########################################
# THE APPLICATION #
##########################################

__________________________________________
// ---------------------------------
// apl.h
// ---------------------------------

HINSTANCE hDLL;

__________________________________________
// ---------------------------------
// apl.cpp
// ---------------------------------

#include "apl.h"
#include "test.h"

// [...]

hDLL = LoadLibrary("test");
typedef CFoo* (*MYFUNC)(DWORD);

if (hDLL != NULL) {
        MYFUNC pnMyfunc = (MYFUNC) GetProcAddress(hDLL, "CreateFoo");
CFoo* pFoo = pnMyfunc(0);
pFoo->Initialize(_T("check"));
        delete pFoo;
FreeLibrary(hDLL);
}

// [...]

##########################################
# THE DLL #
##########################################
__________________________________________
// ---------------------------------
// test.def
// ---------------------------------

LIBRARY "test"
DESCRIPTION 'Test for Windows DLL'

EXPORTS
CreateFoo @1

__________________________________________
// ---------------------------------
// StdAfx.h
// ---------------------------------

#if !defined(AFX_STDAFX_H_9234592646__INCLUDED_)
#define AFX_STDAFX_H_9234592646__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define WIN32_LEAN_AND_MEAN

#include <windows.h>

#endif // AFX_STDAFX_H_9234592646__INCLUDED_

__________________________________________
// ---------------------------------
// test.h
// ---------------------------------

#include <string>

class CFoo {
public:
virtual void Initialize (std::string sName) = 0;
};

__________________________________________
// ---------------------------------
// test.cpp
// ---------------------------------

#include "StdAfx.h"
#include "test.h"

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

class CFooImp : public CFoo {
public:
CFooImp();
virtual ~CFooImp();

void Initialize (std::string sName) {
m_sName = sName;
}

protected:
std::string m_sName;
};

CFooImp::CFooImp() {}

CFooImp::~CFooImp() {}

__declspec(dllexport) CFoo* CreateFoo(DWORD dwVersion) {
if (dwVersion == 0) return new CFooImp;
return NULL;
}