About QTreeVew's expanded() signal

[yangyunzhao]

In my program,when I click the"+", the treeview will emit signal.
But the signal is not as the same as I think. See the picture:


In my opinion,when I click the "+" before "Logic View",the signal's parameter should be "Logic View"'s QMoudelIndex.

But I found that the the signal's parameter was "Logic View"'s parent's QMoudelIndex!

How can I get "Logic View"'s QMoudelIndex when I when I click the "+" before "Logic View"?

Could you give me some helps?Thanks a lot!