ios - UIButton 使用计数器在按下时更改标题

Question

我在下面的代码中遇到错误。我正在用头撞墙，因为我不明白为什么我似乎无法使用按钮按下次数(计数器)更新消息每次按下按钮...

- (IBAction)countButtonTapped:(id)sender {

    self.pressCount+=1;
    //int count = (int)self.pressCount;

    //[self.tapCountButton setTitle:@"I've been tapped %i time(s)!" forState:UIControlStateNormal];
    //[self.tapCountButton setTitle:@"I've hit the main button!" forState:UIControlStateNormal];
    //NSLog(@"I've been tapped %lu time(s)!", (unsigned long)self.pressCount);
    [(UIButton *)sender setTitle:@"I've been tapped %@ time(s)!",self.pressCount forState:UIControlStateNormal];

Answer 1

听起来您只需要一个字符串格式化程序。

试试这个:

- (IBAction)countButtonTapped:(id)sender {
    UIButton * button = (UIButton *) sender; 
    self.pressCount+=1;
    NSString * titleForButton = [NSString stringWithFormat: @"I've been tapped %d time(s)!",self.pressCount]
    [button setTitle: titleForButton forState: UIControlStateNormal];
}

这里的另一个区别是“self.pressCount”可能是一个 NSInteger，所以你想使用“%d”而不是“%@”作为格式参数"，表示 NSString 对象。