为NSArray中的对象运行NSTimer

Question

I have an NSArray of NSObjects . For each object in the NSArray , I'd like to run a timer until it finishes, then restart it for the next object.

The objects in the NSArray will be used to populate UITextField s.

I've tried for (NSObject *myThing in self.ArrayOfMyThings) , it ends up displaying one timer correctly on screen while instantiating a bunch of others. Thank you for reading. I welcome suggestions on how I might go about accomplishing this feat of software engineering ;)

My timer is instantiated in this method:

- (IBAction)startButton:(UIButton *)sender {
    if (self.isPaused == YES) {
        NSLog(@"startButton pressed");
        self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0
                                                      target:[NSBlockOperation blockOperationWithBlock:^{
                [self counting];
        }]
                                                    selector:@selector(main)
                                                    userInfo:nil
                                                     repeats:YES];
        self.isPaused = NO;

    }
}

The timer counts using this method:

- (void)counting {
    // ** If the timer is RUNNING **
    if (self.isPaused == NO && secondsRemaining > 0) {
        secondsRemaining-=1;
        elapsedTime+=1;
        self.timerLabel.text = [self timeFormatted:secondsRemaining];
        NSLog(@"counting: isPaused = %@", self.isPaused ? @"YES" : @"NO" );

        if (secondsRemaining < 4 && secondsRemaining > 0) {
            [self voiceCountdownAlert];
        }
    // ** If the timer is FINISHED **
    } else if (self.isPaused == NO && secondsRemaining == 0) {
        [self resetTimer];
        [self voiceTimerCompleteAlert];
        secondsRemaining = elapsedTime;
        elapsedTime = 0;
        self.timerLabel.text = [self timeFormatted:secondsRemaining];
        NSLog(@"counting: The timer was reset");
    // ** If the timer is paused **
    } else if (self.isPaused == YES) {
        NSLog(@"counting: isPaused = %@", self.isPaused ? @"YES" : @"NO" );
    }
}

This method is how I stop the timer manually:

- (IBAction)stopButton:(UIButton *)sender {
    NSLog(@"stopButton pressed");
    [self.timer invalidate];
    self.timer = nil;
    self.isPaused = YES;
}

Answer 1

I would suggest creating a class property to keep track of the numeric index of the "current" item, eg:

@property (nonatomic) NSInteger currentIndex;

Use this to identify which item in the array you are currently using. When you start, initialize this to 0. Then, in the "timer is finished" routine, just increment your index, make sure you're not at the end of the array. If you're done, then invalidate your timer. If not, just carry on with the new index value.