DLL導出一個c++類，接口方法

#pragma  once

#ifdef MATUREAPPROACH_EXPORTS
#define MATUREAPPROACH_API __declspec(dllexport)
#else
#define MATUREAPPROACH_API __declspec(dllimport)
#endif

class IExport 
{
public:
    virtual void Hi() = 0;
    virtual void Test() = 0; 
    virtual void Release() = 0;
};


extern "C" MATUREAPPROACH_API IExport* _stdcall CreateExportObj();
extern "C" MATUREAPPROACH_API void _stdcall DestroyExportObj(IExport* pExport);

// MatureApproach.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include "MatureApproach.h"
#include "ExportClassImpl.h"


#ifdef _MANAGED
#pragma managed(push, off)
#endif

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;
}

#ifdef _MANAGED
#pragma managed(pop)
#endif

MATUREAPPROACH_API IExport* APIENTRY CreateExportObj()
{
    return new ExportImpl;
}

//這里不能直接delete pExport，因為沒有把IExport的析構函數定義為虛函數
MATUREAPPROACH_API void  APIENTRY DestroyExportObj(IExport* pExport)
{
    pExport->Release();
}

#pragma once

#include "MatureApproach.h"

class ExportImpl : public IExport
{
public:
    virtual void Hi();
    virtual void Test();
    virtual void Release();
    ~ExportImpl();
private:
};

#include "MatureApproach.h"

//#pragma comment(lib, "../debug/MatureApproach.lib")

int _tmain(int argc, _TCHAR* argv[])
{
    IExport* pExport = CreateExportObj();
    pExport->Hi();
    pExport->Test();
    DestroyExportObj(pExport);
    system("pause");
    return 0;
}