How to restrict autodelete in Qt?

[vql]

I am developing a program have the interface same as Office 2007.
I need use many toolbars but only one toolbar display on main window.
When user click on menu File -> I show toolbar fileToolBar
When user click on menu Edit -> I show toolbar editToolBar

mainWin->setToolBar(fileToolBar); // user select menu File
//...
mainWin->setToolBar(editToolBar); // user select menu Edit -> fileToolBar will be deleted
//...
mainWin->setToolBar(fileToolBar); // user reselect menu File but in this case, program will cause error because fileToolBar deleted.

mainWin->setToolBar(fileToolBar); // user select menu File
//...
mainWin->setToolBar(editToolBar); // user select menu Edit -> fileToolBar will be deleted
//...
mainWin->setToolBar(fileToolBar); // user reselect menu File but in this case, program will cause error because fileToolBar deleted.

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Please help me how to solve this problem.