Question

I’m making a FLTK GUI in QtCreator. Please don’t get angry at me for not using Qt to make my GUI, it’s irrelevant.

Anyway, my project type is “Plain C++ Project”, and this is my code (You probably don’t need to read it, but I put it there just in case):

// include headers
#include <Windows.h>
#include <Fl/Fl.H>
#include <FL/FL_Window.h>
#include <FL/Fl_Button.h>
#include <FL/FL_ask.h>
// macro functions
#define UP(x) UNREFERENCED_PARAMETER(x)
// callback function
void callback(Fl_Widget *sender)
{
    sender->label("Thanks!");
}
// main function
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, 
    int nShowCmd)
{
    // UP's
    UP(hInstance);
    UP(hPrevInstance);
    UP(lpCmdLine);
    UP(nShowCmd);
    // window
    Fl_Window *window = new Fl_Window(250, 250, "Derp Window");
    window->begin();
    // button
    Fl_Button *button = new Fl_Button(10, 100, 230, 25, "Click Me!");
    button->callback(callback);
    // run
    window->end();
    window->show();
    int result = Fl::run();
    // delete ptr's
    delete button;
    delete window;
    // return
    return result;
}

When I run this, I get this warning, and two errors (Sorry about the small image, just zoom in your browser if you can’t read it):

I know what a LNK2019 error is, in fact they are probably the bane of my existence. But in this case I have no idea why I am getting this. I think that you should also look at this, it’s the text for my Qt projects .pro file:

TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle
CONFIG -= qt

win32: LIBS += -luser32 -lshell32 -lgdi32 -lole32 -ladvapi32

SOURCES += main.cpp

unix|win32: LIBS += -L$$PWD/../../../Desktop/C++/FLTK/lib/ -lfltk

INCLUDEPATH += $$PWD/../../../Desktop/C++/FLTK/include
DEPENDPATH += $$PWD/../../../Desktop/C++/FLTK/include

This is probably the most important part: I never get any errors, and the program runs fine when I use int main() as my main function.

So, my question is why am I getting this, how do I fix it?

Answer 1

I fixed it by making an “Empty Qt Project” instead of a “C++ Console Application”!