you have to sorround the functions with

if you use MSVS tool chain. Don’t know whether it is also needed for others like gcc etc.

The easiest way to set up a project for a shared library / DLL is to use the Qt Creator New Project… wizard (and select Other Project / C++ Library). That will give you a good starting point with import / export defines etc.

If you want to make it a pure C DLL, the interface obviously has to be pure C, no C++ classes as return values or parameters.

Er.. this (”__declspec(dllexport)” and “__declspec(dllimport)”) is required too.. isn’t it?

MyDllDef.h

MyLib.h

MyApp.cpp

You might also need to use the extern C.. Look at this Stack Overflow [stackoverflow.com] post on it.

Yeah, that’s exactly what you get from the Other Project / C++ Library wizard. That’s what I meant by ‘import / export defines etc.’ (though I agree I could have been a bit more explicit).

@ludde: Sorry about that, I hadn’t used the feature myself, coding in VS at work.. but you’re right the wizard does make it a lot simpler. Cheers :)

[Edit: @gerolf: Thanks for the info.. i noticed the macros in the wizard generated code.. ]

But that’s only needed on windows for MSVC compiler, mingw does it in another way, so I suggest using Q_DECL_EXPORT / Q_DECL_IMPORT. They map to the correct, compiler specific code.