IPhone Message notification-nsnotification and nsnotifcenter Center

1. nsnotification: message or notification

Three member variables

-(Nsstring*) Name;

-(ID) Object;

-(Nsdictionary*) Userinfo;

Notification name: Name,

Message sender: object. The proxy can receive the nsnotification method.Callback to object

Additional information: userinfo

 

2. nsicationicationcenter: Message Center

In Singleton mode, you must use the following methods to access

 
[Nsnotificationcenter defacenter center]
 

3. broadcast a notification

 
[[Nsicationcenter center defacenter center] postnotificationname:@"Aevent" Object: Nil];
 

Send a notification with the accompanying information

[[Nsicationcenter center defacenter center] postnotificationname:@"Event" Object: Nil userinfo :( nsdictionary *) auserinfo];
 

 
Auserinfo is a dictionary
 

Send a notification directly

 
[[Nsicationcenter center defacenter center] postnotification :( nsnotification *) Notification];
 

4. Register a notification listener

 
[[Nsicationcenter center defacenter center] addobserver: Self selector: @ selector (onhandler :) name:@"Aevent" Object: Nil];
 

When registering a notification, you can specify a specific broadcaster object, but it is not required.

5. Remove a listener

[[Nsicationcenter center defacenter center] removeobserver: Self Name:@"Aevent" Object: Nil];
 

6. Notify the method to be called

 
-(Void) Onhandler :( nsnotification *) notif
{
Nsdictionary * user_info = [notif userinfo];
//Execute custom Logic
}