Maintaining the appearance of continuity after an application has been tombstoned is one of the key challenges facing Windows Phone developers.
There are two types of application state: persistent and transient. Persistent state exists across application launches and is saved using your app’s private storage area. Transient state is discarded when an application is closed and is stored in the
Transient page state should be stored when the
Page.OnNavigatedFrom method is called and restored when the
OnNavigatedTo method is called. Transient application state can be stored when the
PhoneApplicationService.Deactivated event occurs and restored when the