How to change UIBarButtonItem's type in UINaviagationBar at runtime?

问题

I am working on an iPhone's view which composed 3 elements, UITextView, UIToolBar with an UIBarButtonItem.

The goal is, I want UIBarButtonItem change its style from 'edit' (UIBarButtonSystemItemEdit) to 'Done' (UIBarButtonSystemItemDone) and update new selector to new method.

First of all, I have tried following code but it doesn't work:

Could you help me on this idea?

回答1:

There is a builtin bar button with this behaviour, you get it via the editButtonItem property of a UIViewContoller. Tabbing that button will change the view controller it came from into editing mode, and toggle the button into a done button.

- (void)viewDidLoad {
  [super viewDidLoad];
  self.navigationItem.rightBarButtonItem = self.editButtonItem;
}

回答2:

If you have added the button through IB then make sure to set the identifier to Custom Also allocate a button in the .h with appropriate IBOutlet and Property Synthesize the button in .m

Then in your code do the following:

// Set to done
editButton.style = UIBarButtonItemStyleDone;
editButton.title = @"Done";

// Set back to edit
editButton.style = UIBarButtonItemStyleBordered;
editButton.title = @"Edit";

回答3:

to change the button the Done button use this

[self.navigationItem.rightBarButtonItem setStyle:UIBarButtonItemStyleDone];

to change the button to Edit button use this

[self.navigationItem.rightBarButtonItem setStyle:UIBarButtonItemStyleBordered];

回答4:

I ended up doing something like this. Unfortunately, setting the title directly did not work, for some reason it was nil and would not let me set it to a different value. The self.editButton comes from an IBOutlet with the target and actions set. This code uses ARC. I hope this helps someone.

        NSString *title = app.settings.editing 
                        ? NSLocalizedString(@"Done", @"")
                        : NSLocalizedString(@"Edit", @"");

        UIBarButtonItemStyle style  = app.settings.editing 
                                    ? UIBarButtonItemStyleDone
                                    : UIBarButtonItemStyleBordered;

        UIBarButtonItem *editButton 
            = [[UIBarButtonItem alloc] initWithTitle:title 
                                               style:style 
                                              target:self.editButton.target 
                                              action:self.editButton.action];

        self.navigationItem.rightBarButtonItem = editButton;

来源：https://stackoverflow.com/questions/1648244/how-to-change-uibarbuttonitems-type-in-uinaviagationbar-at-runtime

标签

iphone

uinavigationbar

uibarbuttonitem