Create a .dll file - c++

Question

I have 4 files:
mySender.h mySender.cpp myReceiver.h myReceiver.cpp
I want to import these 4 file in a .dll project "MyIfa" in VisualStudio 2012.
I create a new project--->win32--->I choose export external symbols in the wizard---->at least the project is created (the new folder is created with all the components).
Now what I need to do?
Add the four file (add existing items) in my project and building?
Add the four file (add existing items) in my project, includes the .h
files (mySender.h, myReceiver.h) and building?
Add the four file (add existing items) in my project, includes the .h
files (mySender.h, myReceiver.h) , add additional directories and
libraries (that I use in mySender.h, myReceiver.h,mySender.cpp,
myReceiver.cpp) in the project properties and building?
this is the new code generated:
IfacomAmqDll.h
// The following ifdef block is the standard way of creating macros which make exporting
// from a DLL simpler. All files within this DLL are compiled with the IFACOMAMQDLL_EXPORTS
// symbol defined on the command line. This symbol should not be defined on any project
// that uses this DLL. This way any other project whose source files include this file see
// IFACOMAMQDLL_API functions as being imported from a DLL, whereas this DLL sees symbols
// defined with this macro as being exported.
#ifdef IFACOMAMQDLL_EXPORTS
#define IFACOMAMQDLL_API __declspec(dllexport)
#else
#define IFACOMAMQDLL_API __declspec(dllimport)
#endif
// This class is exported from the IfacomAmqDll.dll
class IFACOMAMQDLL_API CIfacomAmqDll {
public:
CIfacomAmqDll(void);
// TODO: add your methods here.
};
extern IFACOMAMQDLL_API int nIfacomAmqDll;
IFACOMAMQDLL_API int fnIfacomAmqDll(void);
this is IfacomAmqDll.cpp:
// IfacomAmqDll.cpp : Defines the exported functions for the DLL application.
//
#include "stdafx.h"
#include "IfacomAmqDll.h"
// This is an example of an exported variable
IFACOMAMQDLL_API int nIfacomAmqDll=0;
// This is an example of an exported function.
IFACOMAMQDLL_API int fnIfacomAmqDll(void)
{
return 42;
}
// This is the constructor of a class that has been exported.
// see IfacomAmqDll.h for the class definition
CIfacomAmqDll::CIfacomAmqDll()
{
return;
}
So what I need to do with my existing .h and .cpp file to be able to export all the classes that are defined inside?

Answer 1

If you ran the wizard to create a DLL project with some example exports, you can see the format you need to follow to export classes and/or functions from your dll. It should be as simple as this:
Add your existing source files to the DLL project.
For any class you want to export, #include the generated DLL header file and prepend the #define'ed symbol that resolves to __declspec(dllexport) to the class name.
Rebuild.
For example, the wizard will have generated a header file, say header.h that includes something like this:
// The following ifdef block is the standard way of creating macros which make exporting
// from a DLL simpler. All files within this DLL are compiled with the WIN32PROJECT2_EXPORTS
// symbol defined on the command line. This symbol should not be defined on any project
// that uses this DLL. This way any other project whose source files include this file see
// WIN32PROJECT2_API functions as being imported from a DLL, whereas this DLL sees symbols
// defined with this macro as being exported.
#ifdef WIN32PROJECT2_EXPORTS
#define WIN32PROJECT2_API __declspec(dllexport)
#else
#define WIN32PROJECT2_API __declspec(dllimport)
#endif
Now, suppose you have an existing class called CMyClass in your existing source code:
class CMyClass
{
// ... blah ...
};
If you want to export his class from the dll, do this:
#include "header.h"
class WIN32PROJECT2_API CMyClass
{
// ... blah ...
};