iOS - 在输入过程中验证用户 ip 地址

Question

所以我想在打字时验证用户 ip。在 VC 中，我做了以下操作:

extension NetworkSettingsViewController: UITextFieldDelegate {
  func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    self.staticMask.resignFirstResponder()
    self.staticGateway.resignFirstResponder()
    self.staticIp.resignFirstResponder()
    self.staticDns.resignFirstResponder()
    return true
}

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

    var isValidate: Bool
    //verify deletion not happening 
    if !(range.length == 1) {
        if validatorManager.verifyTarget(test: string) {

            isValidate = true
        } else {
            isValidate = false
        }
    } else {
        isValidate = true
    }
    return isValidate
}

}

这是验证类:

 class ValidatorManager: NSObject {

   func verifyTarget(test: String) -> Bool {
    //        let validIpAddressRegex = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
    let validIpAddressRegex = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])[.]){0,3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])?$"
    let ipTest = NSPredicate(format:"SELF MATCHES %@", validIpAddressRegex)
    print(ipTest.evaluate(with:test))
    return ipTest.evaluate(with:test)
  }
}

我已经尝试了 2 个正则表达式，但没有。我想逐个字符检查一个字符，然后检查所有八位字节的 dot() 之前的所有 3 个字符。

Answer 1

这里有两个功能:第一个检查用户输入的内容是否有效(未完成的 IP)，第二个检查整个内容:

func verifyWhileTyping(test: String) -> Bool {
    let pattern_1 = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])[.]){0,3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])?$"
    let regexText_1 = NSPredicate(format: "SELF MATCHES %@", pattern_1)
    let result_1 = regexText_1.evaluate(with: test)
    return result_1
}

func verifyWholeIP(test: String) -> Bool {
    let pattern_2 = "(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})\\.(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})\\.(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})\\.(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})"
    let regexText_2 = NSPredicate(format: "SELF MATCHES %@", pattern_2)
    let result_2 = regexText_2.evaluate(with: test)
    return result_2
}

在 textField(_ textField: , shouldChangeCharactersIn range:, replacementString string:) 中使用 verifyWhileTyping(test:) 来在输入时进行检查。当用户完成并单击按钮或按下 Enter 键时调用 verifyWholeIP(test:):

//While typing
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    if let text = textField.text {
        verifyWhileTyping(test: text + string)
    }
    //...
}

//When Enter is tapped
func textFieldShouldReturn(_ textField: UITextField) -> Bool {   
    textField.resignFirstResponder()
    if let text = textField.text {
        verifyWholeIP(test: text)
    }
    //...
    return true
}

pattern_1 在用户输入时检查它是否是正确 IP 的开头:

regexText_1.evaluate(with: "0")        //true
regexText_1.evaluate(with: "255")      //true
regexText_1.evaluate(with: "256")      //false
regexText_1.evaluate(with: "10.10.")   //true
regexText_1.evaluate(with: "1.2..")    //false
regexText_1.evaluate(with: "1.2.3.4")  //true
regexText_1.evaluate(with: "1.2.3.4.") //false

至于pattern_2，它评估整个IPv4:

"(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})\\.(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})\\.(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})\\.(25[0-5]|2[0-4]\\d|1\\d{2}|\\d{1,2})"

这里有更多的测试用例:

regexText_2.evaluate(with: "0.0.0.0")    //true
regexText_2.evaluate(with: "1.1.1.256")  //false
regexText_2.evaluate(with: "-1.0.1.2")   //false
regexText_2.evaluate(with: "12.34.56")   //false
regexText_2.evaluate(with: "I.am.an.IP") //false

对于IPv6，这是要使用的正则表达式:[0-9A-Fa-f]{1,4}" in pattern_2 .