还原窗口几何体

This document describes how to save and restore a window's geometry using the geometry properties. On Windows, this is basically storing the result of QWindow::geometry () and calling QWindow::setGeometry () in the next session before calling show() .

On X11, this might not work because an invisible window does not have a frame yet. The window manager will decorate the window later. When this happens, the window shifts towards the bottom/right corner of the screen depending on the size of the decoration frame. Although X provides a way to avoid this shift, some window managers fail to implement this feature.

当使用 Qt Widgets , Qt provides functions that saves and restores a widget window's geometry and state for you. QWidget::saveGeometry () saves the window geometry and maximized/fullscreen state, while QWidget::restoreGeometry () restores it. The restore function also checks if the restored geometry is outside the available screen geometry, and modifies it as appropriate if it is:

void MyMainWindow::closeEvent(QCloseEvent *event)
{
    QSettings settings("MyCompany", "MyApp");
    settings.setValue("geometry", saveGeometry());
    settings.setValue("windowState", saveState());
    QMainWindow::closeEvent(event);
}
void MainWindow::readSettings()
{
    QSettings settings("MyCompany", "MyApp");
    restoreGeometry(settings.value("myWidget/geometry").toByteArray());
    restoreState(settings.value("myWidget/windowState").toByteArray());
}
							

Another solution is to store both pos() and size() and to restore the geometry using QWidget::resize () 和 move() before calling show() , as demonstrated in the 应用程序 范例。