iPhone UINavigationController后退按钮丢失

Question

In am currently creating a Navigation-based application for the iPhone, where the root view of the NavigationController is the main menu (home). There are 3 other views (named View1, View2 and View3), which can be accessed in this manner; main menu -> View1 -> View2 -> View3.

Each of the Views has a 'Home button' that will call 'popToRootViewControllerAnimated' and return to the main menu. When this button is pressed in View2, it returns to the main menu. However, when you go from the main menu to View1, the Back button will be missing. This is the only View that suffers from the problem.

The thing that has brought this around is that we are 'lazily initialising' View1. In other words, we are keeping a reference to View1 in the main menu so that we have it constantly at hand (to keep the state of that view).

The weird thing is that this problem only happens by pressing the 'Home button' from View2. With View3 there is no issue.

In each of the views' 'ViewWillAppear' methods, we have the following code that will add a back button to the view's NavigationBar;

[self.navigationItem.backBarButtonItem release];
UIBarButtonItem* backButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:nil action:nil];
self.navigationItem.backBarButtonItem = backButton;

Does anyone have any idea on how to remedy this problem?

Answer 1

您必须在以前的视图控制器中应用此代码，因为后退按钮取决于导航堆栈中可见视图控制器上方的视图控制器。