Question

我正在该屏幕上创建一个OTP屏幕，我添加了6个文本字段。现在我想限制只输入一个字符＆amp;也想限制用户不要输入任何特殊的字符。下面是我使用的代码，请查看代码＆amp;让我知道出了什么问题？

let notAllowedCharacters = "!@#$%^&*()_+{},./[]?:;";

 func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange,replacementString string: String) -> Bool
    {
        guard let text = textField.text else { return true }
        let newLength = text.characters.count + string.characters.count - range.length
        if newLength <= 1 {

            return true
        }
        else {
            let set = NSCharacterSet(charactersIn: notAllowedCharacters);
            let filtered = string.components(separatedBy: set as CharacterSet).joined(separator: "")
            return filtered == string;
        }
    }

Answer 1

在检查字符长度时，您需要添加NSCharacterSet的控件。否则，如果总有一个字符，则无论字符如何都将始终为真。将您的代码更新为以下内容，它将适用于您：

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange,replacementString string: String) -> Bool {
    guard let text = textField.text else { return true }
    let newLength = text.characters.count + string.characters.count - range.length

    let set = NSCharacterSet(charactersIn: notAllowedCharacters)
    if newLength <= 1 && !(string.rangeOfCharacter(from: set as CharacterSet) != nil) {
        return true
    } else {
        return false
    }
}

限制字符和限制问题快速限制特殊字符？

1 个答案: