iphone SDK: Not sure why I am not receiving UITextField events?

Question

I have defined the controller to receive the events.

@interface salesViewController : UIViewController
    <UITextFieldDelegate>{

However, none of my events are not firing.

 - (void)textFieldDidBeginEditing:(UITextField *)textField
  {
 //this is not getting called
  }

In Interface Builder I assigned the TextField delegate to the salesView.

What am I missing?

Answer 1

what are you trying to accomplish? textFieldDidBeginEditing is messaged whenever the user selects the text field. If you are trying to update a label or something as the user makes edits, you need to setup an observer w/ NSNotificationCenter and watch for the notification that is fired whenever this happens.If you take this approach, make sure to remove the observer once you are done with it

for example:

#pragma mark
#pragma mark -
#pragma mark Notification Observers

- (void)addObservers {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textFieldDidChange:) name:@"UITextFieldTextDidChangeNotification" object:nil]; 
}
- (void)removeObservers {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"UITextFieldTextDidChangeNotification" object:nil];
}

if you need to keep tabs on multiple text fields, do something like this for your selector:

- (void)textFieldDidChange:(NSNotification*)aNotification {
    UITextField *textField = (UITextField *)[aNotification object];
    if([textField isEqual:usernameTextField])
    {   
     [user setUsername:usernameTextField.text];

    }
    else if([textField isEqual:phoneNumberTextField])
    {
     [user setPhoneNumber:phoneNumberTextField.text];
    }
}

Answer 2

You have to set the delegate properly. You observe the protocol, but you need to do this:

@interface YourController : UIViewController<UITextFieldDelegate>   {
    IBOutlet UITextField* field;
}
@end


@implementation YourController
-(void)viewDidLoad
{
    [field setDelegate:self];
}

And you will receive the events. Alternatively, you can set the delegate in Interface Builder as well, along with doing it programmatically in loadView, allocating the field and setting the delegate.

Additionally, try to use NSNotificationCenter as little as possible. Notifications are somewhat obsolete unless there isn't really a direct path between you and the object in question. Just a small comment on the answer above.