Wrong window size when starting the application

[Mikeeeeee]

Hi!
The project is made on Qwidget. When you start the application, not everything fits in the window, but if you rotate the screen 2 times, the widgets are rebuilt and placed in the window.
How make a resize of application when I started ?

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

[Mikeeeeee]

Changed the layout and it magically worked