title: What's the perferred event to handle the end of user interaction with a UIControl?
body: <p>I have a view with multiple dynamically created UITextfields and UISegmented controls on it (but for purposes of this question, there could also be UIButtons, UISwitches, UISliders, or anything else that inherits from UIControl).  I want to preform an action whenever the user finished interacting with any of the controls, regardless of what subclass of control it belongs to.  From looking at other questions, I think I want to use <code>addTarget:action:forControlEvents:</code> to add observers to each of my controls after they are created, but I don't know which event I'm looking for. I've tried all the ones that are listed <a href="http://developer.apple.com/library/ios/#documentation/uikit/reference/UIControl_Class/Reference/Reference.html" rel="nofollow">in the Apple Docs here</a> that seemed relevant but none of them seem to be triggered everytime.  I'm looking for something like <code>.LostFocus</code> in VBA, but I can't seem to find out what that is - I know there is a <code>becomeFirstResponder</code> method to make a control active, but I can't find anything like a "lostFirstResponder" event.</p>
  
  <p>I suppose I could use <code>isKindOfClass</code> to tell what kind of control it is, and set up my event accordingly, but that seems a little sloppy and I feel like there should be a more direct way to do it.  I could also probably set up a UITapGestureRecognizer and build up something that way, but that still feels like a workaround and not really the way it's supposed to be done.</p>