In my project user's can type out the username they want. I will like to restrict this field where they can only use letters, numbers and a underscore (like Instagram). I've searched the internet for hours but can not come up with anything. How can I do this? Thank you in advance!
- 1Have a look at this question which fully describes it :)George– George2018-04-17 21:50:58 +00:00Commented Apr 17, 2018 at 21:50
Add a comment |
1 Answer
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { let s = NSString(string: textField.text ?? "").replacingCharacters(in: range, with: string) guard !s.isEmpty else { return true } let numberFormatter = NumberFormatter() numberFormatter.numberStyle = .none return numberFormatter.number(from: s)?.intValue != nil }