noidea:你可以参见Qt官方文档 Object Trees & Ownership,http://qt-project.org/doc/qt-4.8/objecttrees.html
你的问题可以引用里边一句话来解释
The parent, window, and the child, quit, are both QObjects because QPushButton inherits QWidget, and QWidget inherits QObject ..
(2014-02-26 17:37)