（转载）QT主窗体在屏幕居中显示

（转载）http://blog.csdn.net/xiexiaopingroma/article/details/5791515

#include <QtGui>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QDesktopWidget* desktop = QApplication::desktop();
    int width = desktop->availableGeometry(-1).width();
    int height = desktop->availableGeometry(-1).height();

    MainWindow w;
    w.move((width - w.width()) / 2, (height - w.height()) / 2);
    w.show();

    return a.exec();
}