Put range and avoid special character in a textfield

Question

I am working on iOS. I have a text field on which it should have range to 7 digits, and avoid special characters also. I only want to enter number from 0-9999999. Please help

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{    
       if(range.length + range.location > textField.text.length)
       {
          return NO;
       }

        NSUInteger newLength = [textField.text length] + [string length] - range.length;
        return newLength <= 7;

}

Awesome.Apple · Accepted Answer · 2016-03-09T12:44:52.540

2

Use this

#define acceptableCharacterSet @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:acceptableCharacterSet] invertedSet];

    NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];

    if(![string isEqualToString:filtered])
        return NO;
    NSUInteger newLength = [textField.text length] + [string length] - range.length;
    return (newLength > 7) ? NO : YES;
}

edited Mar 09 '16 at 12:44

answered Mar 09 '16 at 12:33

Awesome.Apple

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But i want range also – Asad Ali Mar 09 '16 at 12:39
range like what?? you mean maxLength? – Awesome.Apple Mar 09 '16 at 12:42
yeah exactly, that was my question – Asad Ali Mar 09 '16 at 12:44
the problem was that, i was returning the filtered string, but your solution works. thanks – Asad Ali Mar 09 '16 at 12:50

score 0 · Answer 2 · answered Mar 09 '16 at 12:32

In your textfield delegate method shouldChangeCharactersInRange

This will only allow 0-9 numbers will not allow alphabets and will not allow special characters

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSCharacterSet *aCharacterSet = [NSCharacterSet characterSetWithCharactersInString:@"0123456789"];
            for (int i = 0; i < [string length]; i++) {
                unichar aCharacter = [string characterAtIndex:i];
                if (![aCharacterSet characterIsMember:aCharacter]) {
                    return NO;
                }
                  return YES;
            }

}

Put range and avoid special character in a textfield

2 Answers2