Question

I have a timer for my project, each time it decrements by 1 second. But if the counter starts working for the second time it gets decremented by 2 seconds and for the third time by 3 seconds etc. what should I do to get 1 sec decrement for all the time?

-(void)viewDidAppear:(BOOL)animated { 

    count=15; //timer set as 15 seconds 
    [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(updateCounter:)userInfo:nil repeats:YES]; //for decrementing timer
}

- (void)updateCounter:(NSTimer *)theTimer { 
    count -= 1; 
    NSString *s = [[NSString alloc] initWithFormat:@"%d", count]; 
    if(count==0) // alert for time expiry 
    { 
       alert = [[UIAlertView alloc] initWithTitle:@"Time Out!!" message:@"Your time is expired." delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil]; 
       [alert show]; 
       self.timer.hidden=YES; 
       [self dismissModalViewControllerAnimated:YES]; 
    } 

    else { 
      self.timer.text = s;
    } 

    [s release]; 
} 

Answer 1

From what you’ve posted, you’re creating multiple timers and not stopping any of them. So after 3 times, you have 3 timers firing each second.

At a minimum, when the timer hits zero you want to invalidate it:

[theTimer invalidate]

But you may also want to consider holding onto the timer you create (in a @property) so that you can invalidate and release it if the user leaves this view some other way before your counter actually goes to zero.

Hope that helps.