Question

我有一个NSTimer，我分别用以下方法暂停和恢复：

-(void) pauseTimer:(NSTimer *)timer {
    self.scene.paused = YES;

    pauseStart = [NSDate date];

    previousFireDate = [timer fireDate];

    [timer setFireDate:[NSDate distantFuture]];
}

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

没有正确重置开火日期，因为当我检查timer.fireDate时，它会显示null。我们想要的只是这些方法暂停计时器并在调用resume方法时从中断处继续计时器。非常感谢任何帮助。

Answer 1

我的解决方案与您的解决方案有一个不同之处。我恢复时重新创建一个计时器。以下是我的工作方式，并且工作得很好：

@property (nonatomic, strong) NSTimer *timer;
@property (nonatomic, assign) NSTimeInterval elapsedTime;
@property (nonatomic, strong) NSDate *startDate;

- (void)startTimer
{
    NSTimeInterval timeInterval = 20.0f;

    // Create a timer. Adjust the elapsed time.
    _timer = [NSTimer scheduledTimerWithTimeInterval:(timeInterval - _elapsedTime)
                                              target:self
                                            selector:@selector(timerFireMethod:)
                                            userInfo:nil
                                             repeats:YES];
    // Save the start date.
    _startDate = [NSDate date];
}


- (void)timerFireMethod:(NSTimer *)theTimer
{
    // Clean.
    [_timer invalidate];
    _timer = nil;
    _elapsedTime = 0.0;

    [self startTimer];

    // Additional handling.
}


- (void)pauseTimer
{
    // Clean.
    [_timer invalidate];
    _timer = nil;

    // Save the elapsed time.
    _elapsedTime = [[NSDate date] timeIntervalSinceDate:_startDate];
}

希望它有所帮助。

NSTimer没有正确暂停和恢复

1 个答案: