iPhone Application Development For Dummies

When to Use Subclassing in iPhone App Development

Subclassing is one of the mechanisms you use to customize behaviors while you're developing your iPhone application. Subclassing involves two stages: (1) creating a new class, called a subclass, that inherits properties from another (super) class and then (2) adding properties as needed for your iPhone application. In general, you’ll want to subclass

• UIView, to create your (more complex) content views, which you may fill with controls, graphics, or the like.

• UIViewController, to manage the content views and connect it to the model.

• NSObject, to create Model views and delegates.

Knowing the Target-Action Patterns for iPhone App Development

Following are the Target-Action patterns that you use when programming iPhone applications. You generally will specify the target as the view controller (which you’ll have already subclassed) because it controls the view in which these controls reside.

• UITabBarItem (for items on the tab bar)

• UIBarButtonItem (for items on the navigation bar and tool bar)

• UIButton

• UIDatePicker

• UIPageControl

• UISegmentedControl

• UITextField

• UISlider

• UISwitch

Using Delegates with Views and Other Classes

When you create iPhone applications, you use delegates to implement application-specific behavior for “generic” views or classes. The table includes all known available delegates used in iPhone application development, though others may be possible. Exceptions to when you need to use a delegate are shown in the Special Use column.