Qt如何设置窗口屏幕居中显示以及设置大小

#include <QDesktopWidget>
 
//.......
QDesktopWidget* desktop = QApplication::desktop(); // =qApp->desktop();也可以
move((desktop->width() - this->width())/2, (desktop->height() - this->height())/2);
//.......

move ((QApplication::desktop()->width() - w.width())/2,
(QApplication::desktop()->height() - w.height())/2);

resize（int width int height）;