How to find if NSTimer is active or not?

Question

I have a timer something like this:

 NSTimer* timer = [NSTimer scheduledTimerWithTimeInterval:1.0                                                    target:self                                                  selector:@selector(updateCountdown)                                                  userInfo:nil                                                   repeats:YES];  

I am updating a label's text using this timer. At a certain condition, I want to check if the timer is active then invalidate the timer. My question is how do I find that timer is active or not?

Answer 1

When a non repeating timer fires it marks itself as invalid so you can check whether it is still valid before cancelling it (and of course then ridding yourself of it).

if ( [timer isValid] && yourOtherCondition){     [timer invalidate], timer=nil; } 

In your case you have a repeating timer so it will always be valid until you take some action to invalidate it. Looks like in this case you are running a countdown so it will be up to you to make sure you invalidate and rid yourself of it when the countdown reaches the desired value (In your updateCountdown method)