Question

I have UITabViewController running with UINavigationController. In each tab i have a different TableViews that are roots of my application tree.

When i click an item of table, it goes to next level viewing another, detailed TableView, still having TabBar and NavigationBar on screen. It works perfectly, except for one thing. If i’m viewing details in one tab, then switch to another tab, and go back again, then i still see my detail. What i want to achieve, is to reset tab after leaving it.

I expect that i have to put something in viewDidUnload or simmilar, but couldn’t find the right solution.

Hope you can help.

Answer 1

at

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController

do

[viewController.navigationController popToRootViewControllerAnimated:YES];

That will navigate the tab’s view controller to the root view whenever the tab is selected.

That’s completely OK to keep your main window view controller (tab bar controller) instance at application delegate.

What you need to add is to set the delegate or whatever other initialized class to be the tab bar controller’s delegate like this:

myTabBarController = [UITabBarController alloc ...
myTabBarController.delegate = self; // the app delegate will be also the tab bar delegate

in the app delegate, then you add the following method to the app delegate:

- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController{
    [viewController.navigationController popToRootViewControllerAnimated:YES];
}

The tab bar controller will call this method whenever it’s tab is selected.
You will also want to make the application delegate confirm UITabBarControllerDelegate this way:

@interface PSAppDelegate : UIResponder <UITabBarControllerDelegate>

that will let the compiler know that app delegate must or might have the methods declared in the protocol and will also give you so convenient auto-complition of this method.