Graphics Programs Reference
In-Depth Information
Notification Center
Every application has an instance of
NSNotificationCenter
, which works like a
smart bulletin board. An object can register as an observer (“Send me 'lost dog' notifica-
tions”). When another object posts a notification (“I lost my dog”), the notification center
forwards the notification to the registered observers (
Figure 8.1
).
Figure 8.1 NSNotificationCenter
