Restricting character input on iPhone UITextField

Question

Possible Duplicate:
allow only alphanumeric characters for a UITextField

Is there a way of only letting the user input letters and numbers, no symbols, via the keyboard into a UITextField?

Daidai, change your UITextField keyboard type to "Name Phone Pad". It will only show Characters or Numbers to input. — Hemang, Apr 03 '12 at 05:46

score 10 · Answer 1 · answered Apr 03 '12 at 06:05

Use this delegate methods.. as It works for me..

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if(textField == YOUR TEXT FIELD)
    {
        NSCharacterSet *invalidCharSet = [[NSCharacterSet characterSetWithCharactersInString:@"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"] invertedSet];
        NSString *filtered = [[string componentsSeparatedByCharactersInSet:invalidCharSet] componentsJoinedByString:@""];
        return [string isEqualToString:filtered];
    }
    else
        return YES;
}

score 2 · Answer 2 · answered Apr 03 '12 at 05:42

2

- (BOOL) textField: (UITextField *)theTextField shouldChangeCharactersInRange: (NSRange)range replacementString: (NSString *)string {    
  //return yes or no after comparing the characters
}

answered Apr 03 '12 at 05:42

Ankit Srivastava

12,347
11
63
115

score 2 · Answer 3 · answered Apr 03 '12 at 05:44

2

Try this:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
 {
   NSCharacterSet *nonNumberSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];
        if(![string stringByTrimmingCharactersInSet:nonNumberSet].length)
        {
            return NO;
        }
   return YES;

}

answered Apr 03 '12 at 05:44

Deviator

688
3
7

This only works for decimals, no? – daihovey Apr 03 '12 at 05:48
1

Yes this code makes sure that the user does not enter any symbol as well as any character. You can modify it according to ur requirement by adding '||' int the if statement and comparing characters. – Deviator Apr 03 '12 at 05:51
looks like you can use NSCharacterSet alphanumericCharacterSet – daihovey Apr 03 '12 at 05:52
this code disables the backspace touches for uitextview (at least for my app). a better solution is using [string rangeOfCharacterFromSet:nonNumberSet].location != NSNotFound in the if statement. – emrahgunduz Aug 29 '12 at 06:36

Restricting character input on iPhone UITextField

3 Answers3