Beginning iOS 5 Application Development

SUMMARY

This chapter explained how you can make use of the Application Preferences feature of the iPhone to save your application preferences to the Settings application. This enables you to delegate most of the mundane tasks of saving and loading an application's preferences settings to the OS. All you need to do is use the NSUserDefaults class to programmatically access the preferences settings.

EXERCISES

1. You have learned that you can use the NSUserDefaults class to access the preferences settings values for your application. What are the methods for retrieving and saving the values?
2. What are the two ways in which you can remove the preferences settings for an application?

Answers to the exercises can be found in Appendix D.

WHAT YOU LEARNED IN THIS CHAPTER

TOPIC	KEY CONCEPTS
Adding application preferences to your application	Add a Settings Bundle file to your project and modify the Root.plist file.
Loading the value of a preference setting	NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; loginName.text = [defaults objectForKey:@“login_name”];
Resetting preferences settings values	Remove the entire application either from the Home screen or via the iPhone Simulator folder on your Mac.
Saving the value of a preference setting	NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; [defaults setObject :loginName.text forKey: @“login_name”]; ...