Setting UIBarButtonItem not changing title, changing only style

问题

I have a UIBarButtonItem in the top right which says 'Edit'. When clicked, this code is called - I know so because the button is emboldened. However, the button's title does not change. Here is my code:

 // set to not editing and change buttons
        [self setEditing:YES animated:YES];
        UIBarButtonItem *doneButton = (UIBarButtonItem *)sender;
        [doneButton setTitle:@"Done"];
        [doneButton setStyle:UIBarButtonItemStyleDone];
        self.navigationItem.rightBarButtonItem = doneButton;

Edit 2:

The following code is doing what I want, however the first time I click the edit button, nothing happens.

-(void)editButton:(id)sender {
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Edit" style: UIBarButtonItemStylePlain target:self action:@selector(edit:)];

}

-(void) edit:(UIBarButtonItem *) barBtnItem
{
    // if not editing
    if (![self isEditing])
    {
        [self setEditing:YES];
        barBtnItem.tag = 1;
        [self.navigationItem.rightBarButtonItem setTitle:@"Done"];
    }
    else
    {
        [self setEditing:NO];
        barBtnItem.tag = 0;
        [self.navigationItem.rightBarButtonItem setTitle:@"Edit"];
    }
}

回答1:

Just do this

UIBarButtonItem *barButton = [[UIBarButtonItem alloc] initWithTitle:@"Edit" style: UIBarButtonItemStyleBordered target:self action:@selector(edit:)];
barButton.tag = 0;
barButton.possibleTitles = [NSSet setWithObjects:@"Edit", @"Done", nil];

Just change state according to click. simple thing.

-(void) edit:(UIBarButtonItem *) barBtnItem
{
     if (barBtnItem.tag == 0)
    {
       barBtnItem.tag = 1;
       [self.navigationItem.rightBarButtonItem setTitle:@"Done"];
    }
    else
    {
        barBtnItem.tag = 0;
        [self.navigationItem.rightBarButtonItem setTitle:@"Edit"];
    } 
}

回答2:

What about this:

self.navigationItem.rightBarButtonItem = self.editButtonItem;

I think it does pretty much what you want it to do.

It changes to "Done" when tapped, and then back to "Edit" when tapped again. Furthermore it sets the view controllers editing property accordingly.

回答3:

You can do it via code as well as follows

UIBarButtonItem *rightBarButton = [[UIBarButtonItem alloc]initWithTitle:@"Done" style:UIBarButtonItemStylePlain target:self action:@selector(doneClicked:)];
self.navigationItem.rightBarButtonItem = rightBarButton;