get notified when UITextField becomeFirstResponder

Question

How I can get notified when UITextField becomeFirstResponder ?

I can check like isFirstResponder or set to to become first Responder by becomeFirstResponder

I want to get notified or handle an event when a user make this text field first responder.

Thanks.

Solution 1

You will need to be come the text field's delegate and implement this optional delegate method:

- (void)textFieldDidBeginEditing:(UITextField *)textField; 

Solution 2

Besides implementing the UITextFieldDelegate method textFieldDidBeginEditing:, you can register for the UITextFieldTextDidBeginEditingNotification notification.

The notification method could be:

- (void)someTextFieldDidBeginEditing:(NSNotification *)notification {
    UITextField *textField = (UITextField *)notification.object;
}

Solution 3

The delegate is definitely the way to go. Unfortunately, in my situation I couldn't use that, because the controller was the delegate of my UITextField subclass and I needed to modify it's placeholder text. Instead I override the methods - (BOOL)canBecomeFirstResponder; & - (BOOL)resignFirstResponder;. Be sure to call super.