QT 子窗口监听主窗口信号（超级简单，但是好用，比如主窗口移动的时候，子窗口不要再继续处理任务）
MainWindow *ptr = NULL; ptr = (MainWindow*)parentWidget(); connect(ptr, SIGNAL(param_result(bool)), this, SLOT(param_add(bool)));
http://blog.csdn.net/emdfans/article/details/42667403
MainWindow *ptr = NULL; ptr = (MainWindow*)parentWidget(); connect(ptr, SIGNAL(param_result(bool)), this, SLOT(param_add(bool)));
http://blog.csdn.net/emdfans/article/details/42667403
