The object associated with the notification.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
This is often the object that posted this notification. It may be
Typically you use this method to find out what object a notification applies to when you receive a notification.
For example, suppose you’ve registered an object to receive the message
handle when the
Port notification is posted to the notification center and that
handle needs to access the object monitoring the port that is now invalid.
handle can retrieve that object as shown here: