删除从QWidget继承的对象，WA_DeleteOnClose分段错误

Question

I'm using an object the inherits QWidget, and in order to know when it is closed, I've used setAttribute(Qt::WA_DeleteOnClose) , and connected

connect(myObj,SIGNAL(destroyed(QObject*)),this,SLOT(handleFinish()));

However, when the object is being deleted, I get munmap_chunk(): invalid pointer , and when I look at the address of the pointer, it is one of the data members of myObj, which is really not a pointer.

I allocate myObj dynamically, so it is supposed to be on the heap - myObj = new myObj(); The error comes at the end of myObj destructor, and I've checked that this is the first time the destructor is called (after looking at When setting the WA_DeleteOnClose attribute on a Qt MainWindow, the program crashes when deleting the ui pointer ).

Any suggestions for dealing with it?

Answer 1

By the time you receive the destroyed signal, the object is only a QObject - not a QWidget and definitely not of any derived type. You can only access the members and methods provided via QObject , not via any other type.

It seems that you wish to be notified when a widget is about to close: for that, install an event filter that intercepts QEvent::close on the widget. See also this answer and a discussion of why a closeEvent cannot be generally handled via a slot .