Using External Lib/DLLs in Qt Creator?

Question

I decided after a bunch of headaches all morning, that using Qt Creator for my first Qt project would probably be better than MSVC (had too many issues compiling).

I

Answer 1

Compiling external libraries with QtCreator/gcc

If you own the source code of your libraries this is the .pro file to make an external library (.dll and .a) or Framework (on Mac OS X) from them:

TEMPLATE = lib

INCLUDEPATH = <your-include-paths>
HEADERS += <your-headers>
SOURCES += <your-sources>
TARGET = MyLib  /* The name of your libary */

/* Win32: To generate a MyLib.dll and libMyLib.a (gcc) or MyLib.lib (MSVC) file */
win32 {
    CONFIG += dll
}

/* Just in case you need to generate Mac Frameworks: */
macx {
    CONFIG += shared lib_bundle
    FRAMEWORK_HEADERS.version = Versions
    FRAMEWORK_HEADERS.files += <your library headers>
    /* Example:
    FRAMEWORK_HEADERS.files += /path/to/your/lib/MyLib.h
    */
    FRAMEWORK_HEADERS.path = Headers
    QMAKE_BUNDLE_DATA = FRAMEWORK_HEADERS
    VERSION = 0.5.0   // a framework version you can define
}

Adding external libraries to your QtCreator/gcc project

/* your project settings */

/* If you compile on windows */
win32 {
    /* If you compile with QtCreator/gcc: */
    win32-g++:LIBS += /path/to/your/libMyLib.a

    /* IF you compile with MSVC: */
    win32-msvc:LIBS += /path/to/your/libMyLib.lib
}

/* If compile on Mac and want to link against a framework */
macx {
    LIBS+= -framework MyLib
    QMAKE_FLAGS += -F/path/to/MyLib
}

Note that to use external libraries with gcc you need the libMyLib.a file that contains the linking information. The libMyLib.lib are generated by MS Visual Studio and can't be processed by gcc afaik!