How to display window form fullscreen on second monitor in Qt?

问题

I m using Qt5 on linux, I want to display window form fullscreen on second screen (dual monitor)? I tried this code but it doesnt work. Is there any other way?

QRect screenres = QApplication::desktop()->screenGeometry(1/*screenNumber*/);
Widget *secondDisplay = new Widget(); // Use your QWidget
secondDisplay->move(QPoint(screenres.x(), screenres.y()));
secondDisplay->resize(screenres.width(), screenres.height());

回答1:

You can use QScreen.

QScreen *screen = QGuiApplication::screens()[1]; // specify which screen to use

SecondDisplay secondDisplay = new SecondDisplay(); // your widget

secondDisplay->move(screen->geometry().x(), screen->geometry().y());
secondDisplay->resize(screen->geometry().width(), screen->geometry().height());
secondDisplay->showFullScreen();

回答2:

One way of doing it in Qt5 is to use QWindow::setScreen to set the screen on which the window should be shown. QWidget has a windowHandle() that returns the pointer to the QWindow.

Here is how to show your widget in the last screen in full-screen mode :

secondDisplay->show();
secondDisplay->windowHandle()->setScreen(qApp->screens().last());
secondDisplay->showFullScreen();

来源：https://stackoverflow.com/questions/26803458/how-to-display-window-form-fullscreen-on-second-monitor-in-qt