재개 기능이 NSTime에서 올바르게 작동하지 않습니다.

에서 timerUpdating당신은 설정 NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:startDate];. 사용자가 타이머를 일시 중지했는지 여부는 고려하지 않습니다.

이 동작을 수정하려면 다음과 같이 할 수 있습니다.

.h에서 (멤버 변수 설정) :

NSTimeInterval pausedTime;

.m (3 줄 편집)

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setUp];
    self.isPaused = NO;
    pausedTime = 0;    //edit
}

- (void) setUp {
    startDate = [NSDate date];
    _timer = [NSTimer scheduledTimerWithTimeInterval: 1.0/100.0 target: self selector: @selector(timerUpdating) userInfo: nil repeats: true];
}

-(void)timerUpdating {
    NSDate *currentDate = [NSDate date];
    NSTimeInterval timeInterval = [currentDate timeIntervalSinceDate:startDate] - pauseTime;//edit
    NSDate *timerDate  = [NSDate dateWithTimeIntervalSince1970:timeInterval];

    NSDateFormatter *dateFormater = [[NSDateFormatter alloc]init];
    [dateFormater setDateFormat:@"mm:ss"];
    [dateFormater setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0.0]];
    NSString *timeString = [dateFormater stringFromDate:timerDate];
    if (self.isPaused == NO){
        _timerLabel.text = timeString;
    }
}


- (IBAction)pauseAction:(id)sender {
    [self pauseTimer:self.timer];
}

- (IBAction)resumeAction:(id)sender {
    [self resumeTimer:self.timer];
}

-(void) pauseTimer:(NSTimer *)timer {
    self.isPaused = YES;
    self.pauseStart = [NSDate date];
    self.previousFireDate = [timer fireDate];
    [timer setFireDate:[NSDate distantFuture]];
}

-(void) resumeTimer:(NSTimer *)timer {        
    self.isPaused =  NO;
    NSDate *currentDate = [NSDate date];
    NSTimeInterval pauseTime = [currentDate timeIntervalSinceDate:pauseStart];
    pausedTime += pauseTime;//edit
    NSDate *neededFireDate = [NSDate dateWithTimeInterval:pauseTime sinceDate:previousFireDate];
    [timer setFireDate:neededFireDate];
    NSLog(@"Fire Date: %@", timer.fireDate);
}