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

I have had the same problem while I was trying to pause & restart a timer. To stop it:

[timer invalidate];
[timer release];
timer = nil;

And to start/ restart it:

timer = [[NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(aSelector) userInfo:nil repeats:YES] retain];

Now it doesn't crash when I invalidate it.