Validate textfield with special character

Question

In my app. I want to validate textfield with Special characters,

Ex. if user press the ? from keypad than user not able to enter the ? in Textfield,

Please any one suggest, How can i do that?

Answer 1

Try like below it will help you.It will accept only letters

   - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
    {
        //For avoiding user to enter non digital number..
        if([[string stringByTrimmingCharactersInSet:[[NSCharacterSet letterCharacterSet] invertedSet]] isEqualToString:@""])
        {
            return NO;
        }
        else
        {
            return YES;
        }
    }