我只想接受我的文本字段中的 A 到 Z。并且不接受 swift 5 中的数字

Question

我创建了一个用户名文本字段，我希望我的文本字段不接受 swift 5

中的数字

我试过这个芽没用

func OnlyCharacter(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
 let allowedcharacters = CharacterSet.decimalDigits
 let characterset = CharacterSet(charactersIn: string)
 return allowedcharacters.isSuperset(of: characterset)

 }

Answer 1

您只需将 CharacterSet.decimalDigits 更改为 NSCharacterSet.letterCharacterSet()

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    if string.rangeOfCharacter(from: .letters) != nil {
        return true
    } else {
        return false
    }
}

Answer 2

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { 
    let non_digits = NSCharacterSet.letters.inverted
    let range = string.rangeOfCharacter(from: non_digits)
    if range != nil { // found an invalid
        return false
    }
    return true
}

Answer 3

 func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
      let characterSet = CharacterSet.letters //accept letters only here
      if string.rangeOfCharacter(from:characterSet.inverted) != nil {
      return false
    }
    return true
 }

我只想接受我的文本字段中的 A 到 Z。并且不接受 swift 5 中的数字

I want to only accept the A to Z in my textfield . And do not accept the numbers in swift 5

textfield

swift