DLLImport variable and library Linking question

Question

Hello All,
I am using a CVI program with an external DLL file.
My program is designed to be able to load a specific DLL file from a collection  of possible files depending on the required task.
I am making a common variable "result" in each DLL fille.
In my CVI program it is defined as int DLLIMPORT result;
In my DLL I have the variable defined as int DLLEXPORT result;
When I use the DLLIMPORT function for my program to get the variable "result" from the DLL, I get error:Undefined symbol "_imp...
If I include the library for one of my DLL's in my CVI program, this error goes away, of coures.
But because I am using multiple DLL's, one at a time, I do not want to link any librarys to a specific DLL.
I haven't had any issues using my DLL's with DLLEXPORT, but DLLIMPORT is giving me this linking issue when I build it.
What can I do to define my DLLIMPORT variable so I can bypass linking a library to my CVI program?
Veni Vidi Duci

Answer 1

I defined a DLLEXPORT variable inside the DLL header file.
In my main program, I have a DLLIMPORT statement in my global header file for my main declaration, and then a EXTERN DLLIMPORT for any additional files in my program.
Basically I have multiple c files
In my main.c file I define MAIN.
In all my C files I include a global.h
Inside global.h I have:
#ifdef MAIN
DLLIMPORT variable;
#else
EXTERN DLLIMPORT variable;
#endif
That's what I was doing. I changed my desgin though.
I moved away from using DLLIMPORT in my program.
I am now passing a pointer to a structure everytime I call my DLL functions using DLLEXPORT, similar to the sample above.
Then my DLL can save data to memory in my main program using that pointer.
As long as my DLL's use consitent formatting (which is the idea), this should be adequate.
I have tested this and so far it works pretty well.
Veni Vidi Duci