I want to create a file that contains and manages the entire UI outside of the main.cpp and its main function.
To start I used the code from this answer, which worked fine from inside the main method.
To prevent information loss I show the code below as well:
#include ...
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QGraphicsScene scene;
QGraphicsView view(&scene);
QGraphicsPixmapItem item(QPixmap("c:\\test.png"));
scene.addItem(&item);
view.show();
return a.exec();
}
I tried to outsource this code into an own class, but after executing the shown code the just created window disappeared again within a few milliseconds without a warning or an error.
To check if I made a mistake within my own class I tried to use this code from an own function within my main.cpp
void initUI(QApplication * application){
QGraphicsScene scene;
QGraphicsView view(&scene);
QGraphicsPixmapItem item(QPixmap(application->applicationDirPath() + "\\graphics\\Theme1\\background.png"));
scene.addItem(&item);
view.show();
}
But the same problem ocurs here. Why does the shown code needs to be executed within the main method, and how could you outsource it?
In case this information helps: I'm running on windows with Qt Creator 3.6.1 based on Qt 5.6.0 (MSVC 2013, 32 bit)
Edit: Here is my main method
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
initUI(&a);
return a.exec();
}
Edit 2: The error does not occur when I add an
application->exec();
Can somebody explain why this happens? What is the difference between the call of application->exec() in the initUI-method and the a.exec() call within the main method?
