iOS 5.1: The Application Life Cycle (Programming iOS Book 2)

In this tutorial you will step through the life of a simple app, learn the states an app enters and leaves during its life cycle, learn the UIApplicationDelegate protocol methods that iOS calls at each transition, and learn what code you need to write in order to facilitate the app’s smooth transition from state to state. Finally, you will learn how to code your app to function in the iOS multitasking environment. The tutorial includes the code for a sample app and a link to the sample app Xcode project, which illustrates the subjects discussed in the tutorial.