Returns the next responder in the responder chain, or
nil if there is no next responder.
- iOS 10.0+
- tvOS 10.0+
The next object in the responder chain or
nil if this is the last object in the chain.
UIResponder class does not store or set the next responder automatically, so this method returns
nil by default. Subclasses must override this method and return an appropriate next responder. For example,
UIView implements this method and returns the
UIView object that manages it (if it has one) or its superview (if it doesn’t).
UIView similarly implements the method and returns its view’s superview.
UIWindow returns the application object. The shared
UIApplication object normally returns
nil, but it returns its app delegate if that object is a subclass of
UIResponder and has not already been called to handle the event.