2.统一的
3.特殊事件
closeEvent(), focusInEvent(), focusOutEvent(), enterEvent(), keyPressEvent(), keyReleaseEvent(), leaveEvent(), mouseDoubleClickEvent(),mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), moveEvent(), paintEvent(), resizeEvent(), QObject::event(), and QObject::timerEvent().
原文：http://www.cnblogs.com/wenkw/p/4114783.html