how to disable a navigation bar button item in iOS

Question

I have created a navigation controller. In the second view (which is pushed), I have some webservice call and placing a overlay view and setting

self.view.use

Answer 1

Latest Swift: To hide the back button, you MUST use:

self.navigationItem.setHidesBackButton(true, animated: false)

Note: This can trigger a bug in the navigation bar that can cause an artifact to appear in place of a hidden back button when transitioning to a view that doesn't have a back button (or has a leftButton in its place). The artifact that appears is either ellipses "..." or the title of the previous viewController on the stack. I believe this bug to be related to the bug documented in apple's own sample code project "CustomizingUINavigationBar", CustomBackButtonViewController.m