Graphics Programs Reference
In-Depth Information
<UINavigationControllerDelegate, UIImagePickerControllerDelegate
,
UITextFieldDelegate>
In
DetailViewController.m
, implement
textFieldShouldReturn:
.
- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
[textField resignFirstResponder];
return YES;
}
It would be stylish to also dismiss the keyboard if the user taps anywhere else on
De-
tailViewController
's
view
. We can dismiss the keyboard by sending the
view
the message
endEditing:
, which will cause the text field (as a subview of the
view
)
to resign as first responder. Now let's figure out how to get the view to send a message
when tapped.
We have seen how classes like
UIButton
can send an action message to a target when
tapped. Buttons inherit this target-action behavior from their superclass,
UIControl
.
You're going to change the
view
of
DetailViewController
from an instance of
UIView
to an instance of
UIControl
so that it can handle touch events.
In
DetailViewController.xib
, select the main
View
object. Open the identity in-
Figure 12.12 Changing the class of DetailViewController's view
Then, open
DetailViewController.h
in the assistant editor. Control-drag from the
view
(now a
UIControl
) to the method declaration area of
DetailViewControl-
ler
. When the pop-up window appears, select
Action
from the
Connection
pop-up menu.
Notice that the interface of this pop-up window is slightly different than one you saw
when creating and connecting the
UIBarButtonItem
. A
UIBarButtonItem
is a
simplified version of
UIControl
- it only sends its target an action message when it is
tapped. A
UIControl
, on the other hand, can send action messages in response to a
variety of events.
