invoke a method on the click of backbutton

Does anyone know how can i invoke a method on the click of the backbarButton of a viewcontroller... wat i have are two table view controllers..one list view and a开发者_StackOverflow社区nother detail view.... the detail view is pushed in to the navigation controller when an item is clicked in the list view. when the Back bar button is clicked i want to invoke a function...

Pls any help will be appreciated..

Refer to the UINavigationController reference. You can set the leftBarButtonItem property to a custom UIBarButtonItem that has the method that you want invoked as the action: when you create a UIBarButtonItem with the initializer that will suit your needs. There are also references to sample projects in the documentation. The NavBar project is probably a good place to start.