从另一个方法调用一个方法，该方法上有一个CADisplayLink

I would like to call from a method 'method1' another method 'method2'. The problem is that there is a CADisplayLink on 'method1' and when I want to call 'method2' from 'method1' it call it at 6Ofps so 60 times per second, but I just want that it call it one time. I know that I have to use BOOL variable but I don't know how to use them . Can anyone help me ? sorry for my english I'm french :/I would like to call from a method 'method1' an