function that runs all the time in xcode?

I want to make a function that is a开发者_开发百科lways running in xcode similar to Unity's "function Update()". is this possible and if so, how.

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You'll want to read up on run loops and NSTimers.

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This code work for me,Hope it will help you!

write this function in your viewDidLoad() method

    [self performSelector:@selector(onTick:) withObject:nil afterDelay:2.0];

And Here is the onTick: Method do whatever you want to run all the time

-(void)onTick:(NSTimer *)timer
  {

  //do something here

  }