ios - 文本字段自动对焦无法正常工作

Question

我有 6 个文本字段文本框。当用户在第一个文本字段中完成输入时，它应该自动进入第二个，依此类推。在这里我的代码帽子不起作用。当我在第一个文本字段中输入值时，值在第二个文本字段中输入..这里是我的代码:

下面的代码是为了在每个文本字段中只输入一个数字。但是在这里我如何添加文本字段响应器......一旦我完成第一个文本字段，等等......

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


        if textField == self.cardTextFieldOne{
        guard let text = textField.text else {return true}

        let newLength = text.characters.count + string.characters.count - range.length
        return newLength <= 1
        }else if textField == self.cardTextFieldTwo{
            guard let text = textField.text else { return true }

            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 1
        }
        else if textField == self.cardTextFieldTwo{
            guard let text = textField.text else { return true }

            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 1
        }
        else if textField == self.cardTextFieldThree{
            guard let text = textField.text else { return true }

            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 1
        }
        else if textField == self.cardTextFieldFour{
            guard let text = textField.text else { return true }
            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 1
        }
        else if textField == self.cardTextFieldFive{
            guard let text = textField.text else { return true }
            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 1
        }
        else if textField == self.cardTextFieldSix{
            guard let text = textField.text else { return true }
            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 1
        }
        else if textField == self.cardTextFieldMonth{
            guard let text = textField.text else { return true }
            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 2
        }
        else if textField == self.cardTextFieldYear{
            guard let text = textField.text else { return true }
            let newLength = text.characters.count + string.characters.count - range.length
            return newLength <= 2
        }
        return true



    }

提前致谢!!

更新

 if textField == self.cardTextFieldOne{


            guard let text = textField.text else {return true}
            let newLength = text.characters.count + string.characters.count - range.length

            if  (string == "") || string.characters.count < 1
            {
                return true //This also allow you to backspace
            }else if  (cardTextFieldOne.text?.characters.count)! >= 1
            {
                cardTextFieldOne.resignFirstResponder();
                self.cardTextFieldTwo.becomeFirstResponder()

                return false
            }


            return newLength <= 1




        }

Answer 1

简单的解决方案

每次更改文本字段时都会调用创建方法，如下图所示，当您右键单击文本字段时，您会看到编辑更改拖动它并创建方法，如下所示

 @IBAction func editing(_ sender: UITextField)
    {
        if sender == yourFirstTextField {
            if sender.text?.characters.count == 1 {
                yourNextTextField.becomeFirstResponder()
            }
        }

    }