The Core iOS Developer’s Cookbook, Fifth Edition

The UIViewController Class

UIViewController is the parent class for view controllers and the one you use to manage your primary views. It is the workhorse of view controllers. You may spend a large part of your time customizing subclasses of this one class. The basic UIViewController class manages each primary view’s lifetime from start to finish and takes into account the changes that the view must react to along the way.

UIViewController instances are responsible for configuring how a view looks and what subviews it displays. Often they rely on loading that information from XIB or storyboard files. Instance methods let you manually create the view layout in code (loadView) or add behavior after a view finishes loading (viewDidLoad).

Reacting ...