Question

Just starting out with an iPhone application using xcode 4.2.

I understand that it is good practice to use a subclass of UIViewController for each view in my application, and I am able to write some basic code in these to test buttons etc on the associated view.

Now I want to perform some action on a text field in one of these views, let’s say I will use the Value Changed event to log the textfield’s contents on each keystroke.

Should I be creating some kind of UITextField controller subclass? Or do I deal with this kind of thing in the existing ViewController subclass that houses the textfield?

If the latter, how do I refer to the textfield in the view controller subclass, and make the connections?

Answer 1

You would use the existing ViewController subclass that houses the textfield. A good rule of thumb is one ViewController per screen of views (not including UINavigationController, Modal screens, uisplitviewcontroller, and popovers).

To refer to it, you would make a property in the .h of your custom UIViewController:

@property (nonatomic,weak) IBOutlet UITextField * myTextField;

Note the IBOutlet keyword. This will allow you to connect it in InterfaceBuilder (or your storyboard). To learn how to connect that I would recommend you watch a video about IBOutlets since its more of a visual thing.