Question

I have always sort of wondered when to use a UIView vs. a UIViewController on the iPhone.

I understand that you shouldn’t use a UIViewController unless it’s a full-screen view, but what other guidelines are there?

For example, I want to build a modal overlay – a screen that will slide into place over the current screen. If this modal overlay is full-screen, should it be a UIViewController? The last time I built something like this, I subclassed UIViewController, but now I wonder if that was correct.

Answer 1

From Apple’s View Controller Programming Guide for iOS:

“The most important role of a view controller is to manage a hierarchy of views. Every view controller has a single root view that encloses all of the view controller’s content. To that root view, you add the views you need to display your content.”

Also:

“There are two types of view controllers:

• Content view controllers manage a discrete piece of your app’s content and are the main type of view controller that you create.
• Container view controllers collect information from other view controllers (known as child view controllers) and present it in a way that facilitates navigation or presents the content of those view controllers differently.

Most apps are a mixture of both types of view controllers.”