How to check if NSTimer has been already invalidated

Question

I have a NSTimer object that I need to invalidate if a user taps on a button or if they exit a view.

So I have:

[myNSTimer invalidate];
         


        

Answer 1

What I usually do is nil-out the member variable holding the timer, either when it fires, or when I invalidate it. Then you can just do:

[myNSTimer invalidate]; 
myNSTimer = nil;

and it'll do the right thing.