You can call NSUserDefaults
from anywhere in your app. This is usually where state information is stored.
If you envision that you might have to store information for a large number of users, you should create a custom database and only rely on . The easiest way to do that is to use Core Data. You can park the managed object context in the application delegate and then access that from anywhere by calling the app delegate.
I would caution you that an iPhone app has a different design pattern than a web app. You shouldn't be thinking in terms of pages and sessions unless you are implementing a web based interface.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…