An event fired when UITabBarController's 'selectedViewController' changes?

When the user changes the selected tab of a UITabBarController, is 开发者_StackOverflow社区there an event fired to indicate that this specific action happened?

I know that viewDidLoad can get fired if the UIViewController wasn't loaded previously and in the case it was, a viewWillAppear gets invoked. But neither of these will tell me that the view was shown because the tab bar was selected.

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You can use tabBar:didSelectItem: while implementing the UITabBarDelegate:

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item