"Go" How the data is passed between Apps view in iOS

Data is passed between view in two main categories: direct and indirect delivery. In which indirect delivery can also define a singleton that is used to share data.

"Old solution before IOS5"

1) Using the proxy mode sub-Viewcontroller Design Agent protocol, define the Protocol interface, the parent Viewcontroller implement the Protocol interface, the implementation of the child Viewcontroller exit when the relevant data updated to the parent view.
2) using the message mechanism of iOS, the parent Viewcontroller registers message sub-viewcontroller to send messages, triggering the parent Viewcontroller message processing.
3) Using database as the middle of the storage medium, sub-viewcontroller state data into the DB, the parent Viewcontroller from the DB to get the data update view.
4) Nsdefault storage with iOS
5) The storage of intermediate data is implemented by defining global variables in Appdelegate.

"Go" How the data is passed between Apps view in iOS