ios - 为什么我的计时器每隔几毫秒消失一次？

Question

您好，我的计时器有问题，我不明白问题出在哪里，问题出在每英里或几秒钟，我的计时器消失了，出现了，我不明白为什么:

 - (void)viewDidLoad {
    [super viewDidLoad];

    self.BtnA.transform = CGAffineTransformMakeRotation( M_PI );
    _timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(substractTime) userInfo:nil repeats:YES];
    [self reset:nil];
}

    - (IBAction)touchBtnA:(id)sender {
    if (enabledA) {
        [self.BtnA setEnabled:NO];
        [self.BtnB setEnabled:YES];
        enabledA = NO;
        enabledB = YES;
        [self.BtnA setAlpha:0.33];
        [self.BtnB setAlpha:1.0];
    } else {
        [self.BtnA setEnabled:YES];
        [self.BtnB setEnabled:NO];
        enabledA = YES;
        enabledB = NO;
        [self.BtnB setAlpha:0.33];
        [self.BtnA setAlpha:1.0];
    }
}

    - (IBAction)touchBtnB:(id)sender {
    if (enabledB) {
        [self.BtnB setEnabled:NO];
        [self.BtnA setEnabled:YES];
        enabledB = NO;
        enabledA = YES;
        [self.BtnB setAlpha:0.33];
        [self.BtnA setAlpha:1.0];

    } else {
        [self.BtnB setEnabled:YES];
        [self.BtnA setEnabled:NO];
        enabledB = YES;
        enabledA = NO;
        [self.BtnA setAlpha:0.33];
        [self.BtnB setAlpha:1.0];
    }
}

    - (void)substractTime {
    if (enabledA) {
        _remainingTimeA--;
        if (_remainingTimeA == 0)
        {
            [self pause:nil];
            [self.BtnA setEnabled:NO];
        }
        [self updateTime:A];
    }

    if (enabledB) {
        _remainingTimeB--;
        if (_remainingTimeB == 0)
        {
            [self pause:nil];
            [self.BtnB setEnabled:NO];
        }
        [self updateTime:B];
    }
}

    - (void)updateTime: (TimerType)type {
    NSInteger time = type == A ? _remainingTimeA : _remainingTimeB;
    NSInteger minutes = time / 600;
    NSInteger seconds = (time/10) % 60;
    NSInteger milliseconds = time % 10;
    if (type == A)
    {
        [self.BtnA setTitle:[NSString stringWithFormat:@"%02d:%02d:%01d",minutes, seconds, milliseconds] forState:UIControlStateNormal];
    }
    else
    {
        [self.BtnB setTitle:[NSString stringWithFormat:@"%02d:%02d:%01d",minutes, seconds, milliseconds] forState:UIControlStateNormal];

    }
}

- (IBAction)pause:(id)sender {
enabledA = enabledB = NO;

}

- (IBAction)reset:(id)sender {
enabledA = enabledB = NO;
[self.BtnA setEnabled:YES];
[self.BtnB setEnabled:YES];
_remainingTimeA = _remainingTimeB = 6000;
[self updateTime:A];
[self updateTime:B];
[self.BtnA setAlpha:1.0];
[self.BtnB setAlpha:1.0];

}

感谢所有人的功能帮助。

Answer 1

您应该知道，NSTimer不会授予您调用选择器的重复间隔(在您的情况下为1.1)的绝对准确性。换句话说，您应该计算当前选择器调用与先前选择器调用之间的差，这将是精确的间隔