How to show window in fullscreen mode?

[victor wang]

Hi, i'm using Qt5.5 on my computer.
This is my code.

QApplication a(argc, argv);
    MainWindow w;
    QScreen *screen =QGuiApplication::primaryScreen();
    QRect screenGeometry = screen->geometry();
    int height1 = screenGeometry.height();
    int width1 = screenGeometry.width();
    qDebug()<<height1;
    qDebug()<<width1;
    w.resize(width1,height1);
    qDebug("mainwindow");
    return a.exec();

It's no problem when compiling.
But when i execute my program main window can't show it up.
Why is this happened?
Please help!

[J.Hilk]

@victor-wang

The reason, that the window does not show is simple.

You do not call anywhere

w.show();

in your main.cpp :)

[victor wang]

@J.Hilk
But is that resize can do the show out ability?

[J.Hilk]

@victor-wang
no, calling resize on a widget does not automatically show the widget.

w.resize(width1,height1);
w.show();
return a.exec();

I'm not even sure if resize is processed if the widget is hidden and not just sheduled to be resized once the widget is shown.

[jsulm]

@victor-wang Also what you are doing is not full screen!
You just maximize the window (for that there is a better way).
If you want to enter full screen read http://stackoverflow.com/questions/25269248/qt-qmainwindow-fullscreen-without-borders

[victor wang]

@J-Hilk
I add show and it's worked.
i'm using resize on not only window but also the other widgets.
It can work for me.
@jsulm
I had used this it work for me too.
Thank you very much.