objective-c - 将秒推到倒数计时器

Question

我创建了一个显示在标签上的倒数计时器，现在我想添加一个功能，让用户按下按钮的 eberytime 它将为倒数计时器增加 30 秒。我试图自己做，但我没有成功（我出错了，有一次它停止了我的计时器）我该怎么做？这是我的代码：

-(IBAction)start:(id)sender
{
    timer = [NSTimer scheduledTimerWithTimeInterval:.01 target:self     selector:@selector(updateTimer:) userInfo:nil repeats:YES];

}

-(void)updateTimer:(NSTimer *)timer
{
    currentTime -= 10 ;
    [self populateLabelwithTime:currentTime];

    if(currentTime <=0)
    {
        [timer invalidate];
        //some code when countdown reach to 00:00:00
    }

}


- (void)populateLabelwithTime:(int)milliseconds {
    seconds = milliseconds/1000;
    minutes = seconds / 60;


    seconds -= minutes * 60;

    NSString * countdownText = [NSString stringWithFormat:@"%@%02d:%02d:%02d", (milliseconds<0?@"-":@""), minutes, seconds,milliseconds%1000];
    countdownLabel.text = countdownText;

}

-(IBAction)addTime:(id)sender
{
    timer = [NSTimer scheduledTimerWithTimeInterval:.01 target:self selector:@selector(addToCurrent:) userInfo:nil repeats:YES];
}

-(void) addToCurrent:(NSTimer *)timerb;
{
    seconds +=10;
    [self populateLabelWithTime:seconds];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    currentTime = 2700;

}

谢谢！

Answer 1

无需在每次单击按钮时重新创建计时器。此外，在我看来，当您尝试将 30 秒添加回计时器时，您不小心修改了秒数而不是 currentTime。

-(IBAction)addTime:(id)sender
{
    currentTime += 30000;
    [self populateLabelWithTime:currentTime];
}