unresolved external symbol visual studio 2010 error - c++

Question

i've implemented with visual studio 2010 professional a solution containing 2 projects; the first called OptDll consist of a dynamic library with a method i want to export, while the second is a exe project, called prova, in order to try the dll.
I've included the correct references and all work fine until i decided to insert in OptDll project a new class (GlobalOutput) in order to create the output parameters i want. When i build the project OptDll no error occurs but when i build the whole solution i get these errors in the prova project:
Error 59 error LNK2019: unresolved external symbol "public: __thiscall GlobalOutput::~GlobalOutput(void)" (??1GlobalOutput##QAE#XZ) referenced in function _main C:\Users\ANTONIO\Desktop\optDll\prova\prova.obj
Error 60 error LNK2019: unresolved external symbol "public: __thiscall GlobalOutput::GlobalOutput(void)" (??0GlobalOutput##QAE#XZ) referenced in function _main C:\Users\ANTONIO\Desktop\optDll\prova\prova.obj
Error 61 error LNK1120: 2 unresolved externals C:\Users\ANTONIO\Desktop\optDll\Debug\prova.exe 1
I read it could be a problem with the class constructor/destructor but i don't fix it.
Below the code of interest.
OptFunDll.h
#ifdef OPTFUNDLL_EXPORTS
#define OPTFUNDLL_API __declspec(dllexport)
#else
#define OPTFUNDLL_API __declspec(dllimport)
#endif
//#include "tool_library.h"
#include "GlobalOutput.h"
namespace optFun
{
// This class is exported from the optFunDll.dll
class myoptFun
{
public:
// funzione che implementa il modulo di ottimizzazione
class OPTFUNDLL_API GlobalOutput;
static OPTFUNDLL_API void scheduling(const char*,const char*,const char*,const char*,GlobalOutput&);
};
}
OptFunDll.cpp
#include "stdafx.h"
#include "optFunDll.h"
#include <stdexcept>
using namespace std;
::Random Particle::_rnd;
::Random ParticleSwarm::_rnd;
namespace optFun
{
void myoptFun::scheduling(const char *pRicette,const char *pWarehouse,const char *pFarmacia,const char *pShaker,GlobalOutput& total){
//here some code...
//class definition
total.CreateDataPrescription(final_list);
total.time=time_output;
GlobalOutput.h
#include <afxwin.h> // MFC core and standard components
#include <afxext.h> // MFC extensions
#include <afxadv.h>
#include <afxdisp.h> // MFC Automation classes
#include <afxdtctl.h> // MFC support for Internet Explorer 4 Common Controls
#ifndef _AFX_NO_AFXCMN_SUPPORT
#include <afxcmn.h> // MFC support for Windows Common Controls
#endif // _AFX_NO_AFXCMN_SUPPORT
#include "GlobalInfo.h"
#include "tool_library.h"
struct DataPrescription{
EDrug NameDrug;
double Dosage;
EContainerType DestType;
ELiquid IdDest;
double CapacityDest;
double Priority;
bool ScaricoShaker;
DataPrescription(){
NameDrug=EDrug_NoDrug;
Dosage=0.0;
DestType= EContainerType_Tot;
IdDest=ELiquid_NoLiquid;
CapacityDest=0.0;
Priority=0.0;
ScaricoShaker=true;
}
DataPrescription(EDrug name,double dos,EContainerType dest,ELiquid ID,double cap_dest,double p,bool _ScaricoShaker){
NameDrug=name;
Dosage=dos;
DestType=dest;
IdDest=ID;
CapacityDest=cap_dest;
Priority=p;
ScaricoShaker=_ScaricoShaker;
}
};
class GlobalOutput{
public:
CArray<DataPrescription> OptList;
time_info time;
GlobalOutput();
~GlobalOutput();
void CreateDataPrescription(vector<ricetta>&);
};
#endif
GlobalOutput.cpp
#include "stdafx.h"
#include "GlobalOutput.h"
GlobalOutput::GlobalOutput(){
time.total_makespan=0;
}
GlobalOutput::~GlobalOutput(){
}
void GlobalOutput::CreateDataPrescription(vector<ricetta>& list){
//DataPrescription tmp;
for(unsigned int i=0;i<list.size();i++){
DataPrescription tmp(list[i].getID(),list[i].getdosage(),list[i].get_destination(),list[i].get_DestType(),list[i].get_CapacityDest(),list[i].getPriority(),list[i].processing_info.scarico_shaker);
this->OptList.Add(tmp);
}
}
and Finally the main of prova project:
#include "stdafx.h"
#include "optFunDll.h"
#include <iostream>
//#include "C:\Users\ANTONIO\Desktop\optDll\optDll\tool_library.h"
using namespace std;
int main()
{
const char *pRicette;
pRicette=new char(NULL);
const char *pWarehouse;
pWarehouse=new char(NULL);
const char *pFarmacia;
pFarmacia=new char(NULL);
const char *pShaker;
pShaker=new char(NULL);
optFun::myoptFun::GlobalOutput total;
optFun::myoptFun::scheduling(pRicette,pWarehouse,pFarmacia,pShaker,total);
return 0;
}
Thanks for your help.
Please let me know if you want more info.
if I comment the code lines under class definition in OptDll.cpp i get these errors:
Error 5 error C2079: 'total' uses undefined class 'optFun::myoptFun::GlobalOutput' c:\users\antonio\desktop\optdll\prova\prova.cpp 23
Error 6 error C2664: 'optFun::myoptFun::scheduling' : cannot convert parameter 5 from 'int' to 'optFun::myoptFun::GlobalOutput &' c:\users\antonio\desktop\optdll\prova\prova.cpp 24
instead if i uncomment the definition of total i obtain also:
9 IntelliSense: incomplete type is not allowed c:\users\antonio\desktop\optdll\optdll\optfundll.cpp 131
Thanks for you availability, I'm new on c++ programming.

Answer 1

You are not actually exporting your class GlobalOutput.
You need to have:
class OPTFUNDLL_API GlobalOutput