问题:

How to implement Push notification in iPhone?

回答1:

The Apple documentation on Push Notifications is very clear, with sample code:

http://developer.apple.com/iphone/library/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Introduction/Introduction.html

回答2:

If you aren't interested in implementing your own server solution for providing push notifications to your client, you might be interested in these solutions:

http://appnotify.com/

http://urbanairship.com/push/

Each charge a fee for push notifications sent, but they also abstract away most of the initial setup complexity and, obviously, the costs associated with maintaining one's own server/bandwidth.

If you're interested in hosting your own solution, I've had success with Apns4r, a Rails plugin: http://github.com/searls/Apns4r

回答3:

There is also an open source python Apple Push Notification server, in case you want to roll your own and don't fancy any of the options that Justin mentioned.

http://leepa.github.com/django-iphone-push/