Tells the responder when one or more touches associated with an event changed.
- iOS 2.0+
- tvOS 9.0+
The event to which the touches belong.
UIKit calls this method when the location or force of a touch changes. Many UIKit classes override this method and use it to handle the corresponding touch events. The default implementation of this method forwards the message up the responder chain. When creating your own subclasses, call
super to forward any events that you do not handle yourself. For example,
If you override this method without calling
super (a common use pattern), you must also override the other methods for handling touch events, even if your implementations do nothing.