问题
Silly thing, I am trying to change the title on a UIBarButtonItem if a certain condition in a for-loop is met. However I'm having trouble.
I've tried
self.barButtonItem.title=@"NewTitle"
and
[self.barButtonItem setTitle:@"New Title"];
I even did a setNeedsDisplay on the view afterwards without any luck. By the way, yes I am getting the old array of buttons from self.navigationBar.items, removing the old button, and setting the new one.
If I change the screen orientation (flip ipad), the button title does change. But otherwise, it stays the same.
Am I missing something?
回答1:
Problem
If u explore the documentation, apple says :
"You should set this property before adding the item to a bar."
For that reason,
cancel_btn.title = "something" // It does not work !
Because u already set the item to the bar.
Solution
//
let theTitle = "something"
//
self.navigationItem.leftBarButtonItem = UIBarButtonItem(title: theTitle, style:
UIBarButtonItemStyle.plain, target: self, action:
#selector(cancelAction))
Now u set the title before adding the item to the bar.
回答2:
I make use of the possibleTitles property of UIBarButtonItem for this.
Try this when you create the button:
self.barButtonItem = [[UIBarButtonItem alloc] init...];
self.barButtonItem.possibleTitles = [NSSet setWithObjects:@"Title 1", @"Title 2", nil];
then later, to change the title, do:
self.barButtonItem.title = @"Title X"; // must be one of the possibleTitles
来源：https://stackoverflow.com/questions/13675859/changing-uibarbuttonitem-title-impossible