ios – UIButton -setTitle：forState：似乎不起作用

我试图动态地更新UIButtons的IBOutletCollection的标题.我期望标题被设置

>选择和’S’字母
>禁用并选择文本“D | S”.

它不工作,所以我打印出了titleForState：s,看起来标题没有正确设置.我是否使用setTitle：forState：正确？

@property (strong,nonatomic) IBOutletCollection(UIButton) NSArray *buttons;
...
- (void)updateUI  // Calling this from IBAction
{
    for(UIButton *button in self.buttons) {
        [button setTitle:@"S" forState:UIControlStateSelected];
        [button setTitle:@"D|S" forState:UIControlStateSelected|UIControlStatedisabled];

        NSLog(@"%@ %@ %@ %@ %d %d",[button titleForState:UIControlStateSelected],[button titleForState:UIControlStatenormal],[button titleForState:UIControlStateSelected|UIControlStatedisabled],button.selected,button.enabled);
    }
}

这是控制台输出：

2013-02-21 21:05:36.070 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.072 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.073 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.073 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.073 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.074 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.074 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.074 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.075 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.075 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.076 Buttons[37130:c07] D|S D|S   0 1
2013-02-21 21:05:36.076 Buttons[37130:c07] D|S D|S   0 1

解决方法

它不工作,因为IB设置归因标题而不是标题.

改为：

NSAttributedString *attributedTitle = [self.myButton attributedTitleForState:UIControlStatenormal];
NSMutableAttributedString *mas = [[NSMutableAttributedString alloc] initWithAttributedString:attributedTitle];
[mas.mutableString setString:@"New Text"];

[self.myButton setAttributedTitle:mas forState:UIControlStatenormal];

或者,或者：

[self.myButton setAttributedTitle:nil forState:UIControlStatenormal];
[self.myButton setTitle:@"New Text" forState:UIControlStatenormal];

(第二个选项不会保留格式.)