问题:

As mentioned in the title, how do I implement such a functionality?

I am using the code below, (in my viewDidLoad), to get the button on my Navigation Controller of my main view.

UIButton* infoButton = [UIButton buttonWithType:UIButtonTypeInfoLight];

[infoButton addTarget:self action:@selector(viewWillAppear:) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:infoButton];

Not sure how I can get it displayed in all my views.

回答1:

Each view pushed to the navigation stack has an own navigation bar. So I afraid you have to add this button to each navigation bar, when you create a view and before you push this view to the navigation stack.

回答2:

You could simply add an info button to the window, instead of creating a new button for each view controller. Since the window never changes, the button will always be on screen. You only have to take care that no other views are on top of the button.

回答3:

I would suggest you create an base view controller, and add the bar button to your navigationItem in viewDidLoad. Then all your view controllers subclass from the base controller, rather than the default UIViewController. This should solve your problem.