Problem about using Designer to create menu,add action and slot?

[wysota]

i am a newer of qt,and use designer,i found i can add some menu and sub menu of the mainwindow,can add a action to each menu item and a slot of the action,but i does not work,what is the matter?

What does not work?

It seems you menuSYSTEM is a menu and not an action. You probably added a submenu to your SYSTEM action (which caused it to be transformed into a menu) and then deleted it (but the menu was not converted back into an action automatically). Go back to Designer, delete the menu entry and create it again.