From http://devbean.blog.51cto.com/448512/194442

QtSlot

#include <QtGui/QApplication>
#include <QtGui/QPushButton>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QPushButton *button = new QPushButton("Quit");
    QObject::connect(button, SIGNAL(clicked()), &a, SLOT(quit()));
    button->show();
    return a.exec();
}