Qt migrating code from Linux to Windows

There is perhaps a problem with the separator ('\' on Windows and '/' on Linux) on your .pro file. So try this in your project file :

#TEMPLATE, CONFIG, HEADERS, ...

win32 { # For Windows
    # Leave an empty line because of the backslash at the end of the variable
    SEPARATOR = \\

}

linux-g++ { # For Linux
    SEPARATOR = /
}

ID3_FOLDER = .$${SEPARATOR}idlib$${SEPARATOR}id3lib-3.8.3$${SEPARATOR}

LIBS += -id3 -L$${ID3_FOLDER}src$${SEPARATOR}.libs

INCLUDEPATH += $${ID3_FOLDER}include $${ID3_FOLDER}src$${SEPARATOR}.libs

Edit : it is about the flag of your library. If the file containing it is called myLib.dll on Windows (or myLib.so on Linux), you should write -lmyLib. In your project file , I don't see somthing like -lsthg but -id3.

Thanks you for responses! I marked one of the answers as appropriate and I add this answer for clarifying what kind of problem I had exactly.

All that I did to fix problem:

I defined in the main.cpp (main file with source code from that all programme is controlled)

    #define ID3LIB_LINKOPTION 3
    #define ID3_CPP_EXPORT 1

After that I got near 42 errors, but fortunately, they were new.

I found what's wrong only thanks to intuition (maybe), because internet is overloaded with such type errors, but they don't throw any light at the cause of the problem.

I defined header windows.h in the main.cpp (but it has to be before any other header, otherwise zillions of errors, who could think about! )

So, the first lines of your main.cpp file should look like:

    #define ID3LIB_LINKOPTION 3
    #define ID3_CPP_EXPORT 1
    #include <windows.h>
    #include "id3/tag.h"

And it works fine. Hope this will help someone at one day.

DON"T TRY TO USE THAT LIBRARY FROM QtCREATOR !!!! only VS studio c++, I spent many time trying to compile it with Mingw compiler,but source code that is compiled with Mingw can't be linked with libraries generated by microsoft visual studio because of different ABIs