what's the events of getting and losting focus in a view controller

Question

There are 2 forms in my program. When view controller A gets the focus and be active, view controller B will lost the focus and be inactive. Can anyone show me What the events are?

Thanks

Answer 1

Miken, it depends on what type of objects you are using for your "forms".

The simplest "form" to use is a UITextField, and in that case, events will be sent to your UITextField's delegate. In a lot of simple cases, you will designate the viewController that holds your UITextfield to be the UITextFieldDelegate. For more information on the methods that the delegate has, take a look at this: https://developer.apple.com/library/ios/documentation/uikit/reference/UITextFieldDelegate_Protocol/UITextFieldDelegate/UITextFieldDelegate.html#//apple_ref/occ/intf/UITextFieldDelegate

In this case, when the text field gets the focus (ie the user clicks on the text field to edit it) the delegate methods:

– textFieldShouldBeginEditing:

– textFieldDidBeginEditing:

– textFieldShouldEndEditing:

– textFieldDidEndEditing:

will be called. I'm using this as a basic example, and not assuming too much here, but generally you should be looking into your "forms" delegate methods.