UITextField ignoring inputDelegate?

问题

Does UITextField ignore the inputDelegate? Using the following code:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.textField.inputDelegate = self;
    NSLog(@"textField: %@", self.textField);
    NSLog(@"delegate: %@", self.textField.inputDelegate);
}

I get the following output:

2012-03-26 20:43:49.560 InputTest[33617:f803] textField: <UITextField: 0x6c093a0; frame = (20 20; 280 31); text = ''; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x6c094d0>>
2012-03-26 20:43:49.561 InputTest[33617:f803] delegate: (null)

It runs just fine, without warning or exception, and the delegate property works just fine. But setting the inputDelegate causes no change and the delegate methods are not called.

回答1:

I have the same problem as you are facing. upon deep searching i found out that, though UITextInput Protocol was there in iOS 3.2 but UITextView/Field didn't make use of that protocol before iOS 5. Run your code in iOS 5 or later and it should work.

回答2:

Set your delegate after the editing session has begun.

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    [self.myTextfield setInputDelegate:self];
    NSLog(@"Inputdelegate is: %@", self.myTextField.inputDelegate);

    return YES;

}

来源：https://stackoverflow.com/questions/9883137/uitextfield-ignoring-inputdelegate