B<br><br>ased Based on the information outlined in the chapter entitled Understanding Android Application and Activity Lifecycles it is now evident that the activities that make up an application pass through a variety of different states during the course of the application’s lifespan. The change from one state to the other is imposed by the Android runtime system and is, therefore, largely beyond the control of the activity itself. That said, in most instances the runtime will provide the activity in question with a notification of the impending state change, thereby giving it time to react accordingly. In most cases, this will involve saving or restoring data relating to the state of the activity and its user interface.
The primary objective of this chapter is to provide a high-level overview of the ways in which an activity may be notified of a state change and to outline the areas where it is advisable to save or restore state information. Having covered this information, the chapter will then touch briefly on the subject of activity lifetimes.
9.1 The Activity Class
