iPhone - How to save each view controller?

When my app's “applicationWillTerminate” function is called in the app’s delegate file I need to loop through each child controller of a tab controller and save the current state it is in.开发者_如何学Go Is it possible to loop through each viewController calling a custom save function?

Get the tabBarController.viewControllers and send the makeObjectsPerformSelector:@selector(yourCustomSaveMethod) message to that array.

Have a look at UIApplicationWillTerminateNotification and UIApplicationDidEnterBackgroundNotification. Much nicer than looping through your view controllers.