The user information dictionary associated with the notification.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
The user information dictionary stores any additional objects that objects receiving the notification might use.
For example, in AppKit,
NSControl objects post the
text whenever the field editor (an
NSText object) changes text inside the
NSControl. This notification provides the
NSControl object as the notification's associated object. In order to provide access to the field editor, the
NSControl object posting the notification adds the field editor to the notification's user information dictionary. Objects receiving the notification can access the field editor and the
NSControl object posting the notification as follows: