按钮倒计时

首先声明啊,我是一个 iOS 小白,刚开始写.
但是,我发到微博上面的代码都是自己亲手写的,亲测可用,请放心使用

@property (weak, nonatomic) IBOutlet UIButton *btn;
@property (nonatomic , assign) NSInteger count;

- (IBAction)btn:(id)sender {
    _btn.enabled = NO;
    _count = 5;
    [_btn setTitle:@"5秒后重新获取" forState: UIControlStateDisabled];
    [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerFire:) userInfo:nil repeats:YES];
}

- (void)timerFire:(NSTimer *)timer
{
    if (_count != 1) {
        _count -= 1;
        [_btn setTitle:[NSString stringWithFormat:@"%ld秒后重新获取" , (long)_count] forState:UIControlStateDisabled];
    } else
    {
        [timer invalidate];
        _btn.enabled = YES;
        [_btn setTitle:@"点击重新获取" forState: UIControlStateNormal];
    }
}

这样写出来的按钮倒计时,每次跳动的时候,文字会闪烁.解决办法是把按钮的状态设置为 Custom,就好了.
当然了,其他的比如在倒计时过程中,按钮的背景颜色等等,我就不细说了.