Problems using a DLL

[prosass]

Thanks fullmetalcoder for your answer. The problem is I didn´t create the Dll and I cannot modify it to include the Q_DECL_EXPORT and the Q_DECL_IMPORT. Is there any way I can still use the DLL?

[fullmetalcoder]

Thanks fullmetalcoder for your answer. The problem is I didn´t create the Dll and I cannot modify it to include the Q_DECL_EXPORT and the Q_DECL_IMPORT. Is there any way I can still use the DLL?

Sounds weird... You mean that you grabbed a dll from some piece of software and want to use it? In this case you will need a SDK (header files and, under Window$, import library) and Qlibrary won't help you if the symbols (functions/classes) you are interested in are not exported using __declspec() (or any equivalent macro)...

[prosass]

I got the DLL from a student at my university who was working on the same piece of hardware and all I got was the file .h with the functions I can use and the Dll itself.
At the moment I don´t think I´m using QLibrary. In the .cpp file I just try to access the functions by calling them:

int err = 0;
        err = loc_ini();
 
        while (1) {
             //Sleep(1);
             err = loc_getposition(&loc_pos);
             //Sleep(500);
             cout << "Posicion x:" << loc_pos.x << endl;
             cout << "posicion y:" << loc_pos.y << endl << endl;
        }
}

int err = 0;
        err = loc_ini();

        while (1) {
             //Sleep(1);
             err = loc_getposition(&loc_pos);
             //Sleep(500);
             cout << "Posicion x:" << loc_pos.x << endl;
             cout << "posicion y:" << loc_pos.y << endl << endl;
        }
}

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This was enough in Code::blocks but it doesn´t work in QT/VisualStudio. Should I use something like:

QLibrary Sniffer("Sniffer");
 
typedef void (*MyPrototype)();
 MyPrototype myFunction = (MyPrototype) myLib.resolve("mysymbol");
 if (myFunction)
     myFunction();

QLibrary Sniffer("Sniffer");
 
typedef void (*MyPrototype)();
 MyPrototype myFunction = (MyPrototype) myLib.resolve("mysymbol");
 if (myFunction)
     myFunction();

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Should I use something like that?

[fullmetalcoder]

I got the DLL from a student at my university who was working on the same piece of hardware and all I got was the file .h with the functions I can use and the Dll itself. This was enough in Code::blocks but it doesn´t work in QT/VisualStudio.

Which files exactly do you received??? I'm particularly interested in extension like .a or .lib
AFAIK if the compile-time linking doesn't work there are not much chances for it to work at run-time but I might be proved wrong here...

[prosass]

I got the loc.h file that I wrote down in the beggining, the sniffer.dll and the following main.cpp:

#include "loc.h"
#include <windows.h>
#include "iostream.h"
 
loc_position_t loc_pos;
 
int main(void) {
 
        int err = 0;
        err = loc_ini();
 
        while (1) {
             //Sleep(1);
             err = loc_getposition(&loc_pos);
             //Sleep(500);
             cout << "Posicion x:" << loc_pos.x << endl;
             cout << "posicion y:" << loc_pos.y << endl << endl;
        }
}

#include "loc.h"
#include <windows.h>
#include "iostream.h"

loc_position_t loc_pos;

int main(void) {

        int err = 0;
        err = loc_ini();

        while (1) {
             //Sleep(1);
             err = loc_getposition(&loc_pos);
             //Sleep(500);
             cout << "Posicion x:" << loc_pos.x << endl;
             cout << "posicion y:" << loc_pos.y << endl << endl;
        }
}

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That is all I got, do I also need a .lib file to make it work?

[fullmetalcoder]

I got the loc.h file that I wrote down in the beggining, the sniffer.dll and the following main.cpp:
That is all I got, do I also need a .lib file to make it work?

Well, AFAIK window always require an import library to achieve linking against a dll. The file extension of these libs is .lib for MSVC and .a for gcc/mingw. If your friend did not give you such a lib you should ask for one or for the full sources...