UITextFieldDelegate stops working after first activation of UITextField

I have a UITextField which I made here:

text_field = [[UITextField alloc] initWithFrame:CGRectMake(10, 8, 260, 40)];
text_field.delegate = [[MessageInputDelegate alloc] init];

The delegate implementation:

@implementation MessageInputDelegate

- (BOOL) textFieldShouldReturn: (UITextField *) text_field{
    [the_view5 becomeFirstResponder];
    the_view5->text_area.frame = CGRectMake(20, 320, 280, 40);
    the_view5->message_label.frame = CGRectMake(0, 0, 320, 320);
    text_field.enabled = NO;
    text_field.text = @"";
    return YES;
}

- (void) textFieldDidBeginEditing: (UITextField *) textField{
    printf("DID CALL EDIT METHOD\n");
    the_view5->text_area.frame = CGRectMake(20, 140, 280, 40);
    the_view5->message_label.frame = CGRectMake(0, 0, 320, 140);
}

- (BOOL) textField: (UITextField *) textField shouldChangeCharactersInRange: (NSRange) range replacementString: (NSString *) string{
    if (textField.text.length >= 400 && range.length == 0){
        return NO;
    }
    return YES;
}

@end

It works the first time I activate the text field bu开发者_StackOverflowt not the second time...?

Thankyou.

If you're cerating text_field from yout MessageInputDelegate, you should use

text_field.delegate = self;

and declare delegate for both UITextFields.

If yoy create it from other class, you should declare a MessageInputDelegate instance somewhere in your .h file, e.g

MessageInputDelegate *mid;

and then

text_field.delegate = mid;

I used endEditing to close the keyboard and it works.