Notifies this object that it has been asked to relinquish its status as first responder in its window.
- iOS 2.0+
- tvOS 9.0+
The default implementation returns
true, resigning first responder status. You can override this method in your custom responders to update your object's state or perform other actions, such as removing the highlight from a selection. You can also return
false, refusing to relinquish first responder status. If you override this method, you must call
super (the superclass implementation) at some point in your code.