[ios]change title of back button on navigation bar

Question

So I want to change the text on the back button of a UIViewController, and I want it to satisfy the following criteria:

1. Text can be changed dynamically, after the view is presented.
2. Right swipe gesture from left edge of screen still works.

So far the answer I found is either How do I change the title of the "back" button on a Navigation Bar which is unable to change the text dynamically

or this https://stackoverflow.com/a/498089/2925345 which removes the swipe gesture.

Is there any way to satisfy both of the criterias?

Thanks

Answer 1

If not overridden, left button in navigation bar is constructed from navigationItem.backBarButtonItem of previous view controller. To change the text, you need to do something like

NSInteger count = self.navigationController.viewControllers.count;
if (count >= 2) {
    UIViewController* previousVC = self.navigationController.viewControllers[count-2];
    previousVC.navigationItem.backBarButtonItem.text = @"new text";
}

Answer 2

Try this

 UIBarButtonItem *newBackButton =
[[UIBarButtonItem alloc] initWithTitle:@"NewTitle" style:UIBarButtonItemStylePlain
                                target:nil
                                action:nil];
[[self navigationItem] setBackBarButtonItem:newBackButton];

Answer 3

Finally solved this by assigning a delegate to UINavigation Controller's interactivePopGestureRecognizer . And it must be executed in or after viewWillAppear , in this particular order

self.navigationItem.backBarButtonItem = backButton;
self.navigationController.interactivePopGestureRecognizer.delegate = self;

Once I did that I can change the title of backBarButtonItem however I want.

Got my answer from

http://blog.csdn.net/zhaoxy_thu/article/details/15811189

I don't know how it works, I don't know why simply assigning a delegate to a swipe gesture recognizer enables the title of back button to be customizable, I simply followed the instructions in this magical blog post. Thanks zhaoxy_thu for making this work.