C / C++ / MFC

// the DLL: just a bit more of the Visual Studio generated Skeleton
#ifdef CPPDLL_EXPORTS
#define CPPDLL_API __declspec(dllexport)
#else
#define CPPDLL_API __declspec(dllimport)
#endif

// This class is exported from the CppDll.dll
class CPPDLL_API CCppDll 
{
public:
  CCppDll(void);
  virtual int foo();
  virtual int goo(int x)=0;
};

// the dumb test application
#include "stdafx.h"
#include "..\\..\\CppDll\\CppDll\\CppDll.h"
#include <iostream>
using namespace std;


class MyDer: public CCppDll
{
public:
  int goo(int x){ return x*x;}
    
};

int _tmain(int argc, _TCHAR* argv[])
{
  
  MyDer m;
  cout << m.foo() << " " << m.goo(5) << endl;
	return 0;
}

john5632 wrote:

EXPORTS
sum @1

john5632 wrote:

1. But I need to use only .h and .dll file then why .lib file is needed.

john5632 wrote:

2. After adding lib file instaed of dll file, I am getting the error:

error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall CCppDll::CCppDll(void)" (__imp_??0CCppDll@@QAE@XZ) referenced in function "public: __thiscall MyDer::MyDer(void)" (??0MyDer@@QAE@XZ)

class CMyClass
{
public:
    void MyMemberFunction () = 0;
    ...
};