title: Is there any problem unhooking a delegate from an event which was never hooked?
body: <p>I am using standard windows forms controls under C#.</p>
  
  <p>I have two controls which are different ways of setting a single value.  Thus when one is changed, the changed event handler computes a value for the other and sets it.  So I need to unhook the change event on the second control temporarily to prevent looping (A changes B, B is changed so it changes A, A is changed...).  There are also some other situations where I need to stop the change event.  So there are several places where I need to unhook the event, and only one place where it needs to be hooked.</p>
  
  <p>My question is: do I need to keep track of whether the event has been hooked or can I just unhook it as many times as I like and only occasionally hook it again?  (Is there any documentation that addresses this?)</p>