create and use shared library in qt

[bibhukalyana]

Hi everyone,
I tried to create and use a shared library in qt.I used the c++ library project to create this.

code used to create a shared library:

.pro file:

QT       -= gui
 
TARGET = myLIB
TEMPLATE = lib
 
DEFINES += MYLIB_LIBRARY
 
SOURCES += mylib.cpp
 
HEADERS += mylib.h\
        myLIB_global.h

QT       -= gui

TARGET = myLIB
TEMPLATE = lib

DEFINES += MYLIB_LIBRARY

SOURCES += mylib.cpp

HEADERS += mylib.h\
        myLIB_global.h

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.h file

class MYLIBSHARED_EXPORT MyLIB {
public:
    MyLIB();
    int add(int x,int y);
};
 
extern "C"
{
    int sub(int x,int y);
}

class MYLIBSHARED_EXPORT MyLIB {
public:
    MyLIB();
    int add(int x,int y);
};

extern "C"
{
    int sub(int x,int y);
}

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.cpp file :

MyLIB::MyLIB()
{
}
int MyLIB::add(int x, int y)
{
    return x+y;
}
 
int sub(int x, int y)
{
    return x-y;
}

MyLIB::MyLIB()
{
}
int MyLIB::add(int x, int y)
{
    return x+y;
}

int sub(int x, int y)
{
    return x-y;
}

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In my test application i am able to use sub function.code is

typedef int (*pf)(int,int);
    pf fun=(pf)QLibrary::resolve("./libmyLIB.so","sub");
    int x=fun(20,10);

typedef int (*pf)(int,int);
    pf fun=(pf)QLibrary::resolve("./libmyLIB.so","sub");
    int x=fun(20,10);

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It is working.
But when i am trying to use isLoaded function it is returning false.

QLibrary myLib("./libmyLIB.so");
ok=myLib.isLoaded();

QLibrary myLib("./libmyLIB.so");
ok=myLib.isLoaded();

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My problem is i want to use the function directly without using QLibrary.(only adding in .pro file)
How i will use add function in my application ?

[Lykurg]

See in the qmake documentation for LIBS, include the header file of your library and use your library classes as usual.

[bibhukalyana]

thanks for reply.Can you tell me what should be written in .h file.One prototype or any thing extra.

[Lykurg]

In your case you probably only have to use

#include "mylib.h"

#include "mylib.h"

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[bibhukalyana]

thanks it is working.