UITextfield 键盘只有字母，没有数字，没有大写字母，没有空格键？

Question

我希望 UITextfield 的键盘只有 az，没有数字，没有特殊字符（,@$.@$@.#），也没有大写字母。 基本上我想要一个只有字母表的键盘。

我已经能够禁用空间了。 有人知道如何禁用数字、特殊字符和大写字母吗？ 任何这些的解决方案都会很棒。

对所有字符执行以下操作的最佳解决方案是我不想要的吗？

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {

    if (string == " ") {
        return false
    }

    if (string == "1") {
        return false
    }

    return true
}

Answer 1

一种简单的方式是：

if let range = string.rangeOfCharacterFromSet(NSCharacterSet.letterCharacterSet())
    return true
}
else {
    return false
}

Answer 2

Swift 3解决方案

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

     let characterSet = CharacterSet.letters

     if string.rangeOfCharacter(from: characterSet.inverted) != nil {
         return false      
     }
     return true
}

Answer 3

Swift 3带空格

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

Answer 4

Swift 4.2代码如果用户想要删除错误的字符，则只允许字母表允许退格

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

Answer 5

希望仅允许空格，大写和退格的用户的更新

Swift 4.x，Swift 5.x及以上

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    if range.location == 0 && string == " " { // prevent space on first character
        return false
    }

    if textField.text?.last == " " && string == " " { // allowed only single space
        return false
    }

    if string == " " { return true } // now allowing space between name

    if string.rangeOfCharacter(from: CharacterSet.letters.inverted) != nil {
        return false
    }

    return true
}

Answer 6

class ViewController: UIViewController,UITextFieldDelegate {  

     @IBOutlet var phoneTextField:UITextField!

    override func viewDidLoad() {
            super.viewDidLoad() 
    self.phoneTextField.delegate = self
    }

     func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool
           {
                let textString = (textField.text! as NSString).replacingCharacters(in: range, with: string)

                if textField == self.phoneTextField  && string.characters.count > 0 {
                    let LettersOnly = NSCharacterSet.Letters
                    let strValid = LettersOnly.contains(UnicodeScalar.init(string)!)
                    return strValid && textString.characters.count <= 10
                }
                return true
            }
    }

试试这个代码
在上面的代码中只允许在文本字段中使用10个字符

Answer 7

if isValidInput(Input: yourtextfieldOutletName.text!) == false {
    let alert = UIAlertController(title: "", message;"Name field accepts only alphabatics", preferredStyle: UIAlertControllerStyle.alert)
    alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))

    self.present(alert, animated: true, completion: nil)
}

func isValidInput(Input:String) -> Bool {
    let myCharSet=CharacterSet(charactersIn:"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
    let output: String = Input.trimmingCharacters(in: myCharSet.inverted)
    let isValid: Bool = (Input == output)
    print("\(isValid)")

    return isValid
}

Answer 8

当用户没有复制并粘贴到文本字段中以便复制和粘贴到工作时使用打击代码时，所有答案都有效

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    let text = (textField.text! as NSString).replacingCharacters(in: range, with: string)
    let Regex = "[a-z A-Z ]+"
    let predicate = NSPredicate.init(format: "SELF MATCHES %@", Regex)
    if predicate.evaluate(with: text) || string == ""
    {
        return true
    }
    else
    {
        return false
    }

}

Answer 9

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { 让文本 = (textField.text.as NSString):replacingCharacters(in, range: with.string) let Regex = "[az AZ ]+" let predicate = NSPredicate:init(format, "SELF MATCHES %@". Regex) if predicate:evaluate(with.text) || string == ""{ textField.text = textField?text.:replacingOccurrences(of, " ": with: "") return true } else{ return false } return true }