Question

有效的电话号码包含：

少于9个字符，一开始就是“+”，只有数字。

我试图使用正则表达式但我只是开始使用它们并且我不擅长它。我到目前为止的代码是：

static void Main(string[] args)
{
    Console.WriteLine("Enter a phone number.");
    string telNo = Console.ReadLine();

    if (Regex.Match(telNo, @"^(\+[0-9])$").Success)
        Console.WriteLine("correctly entered");

    else
        Console.WriteLine("incorrectly entered");

    Console.ReadLine();
}

但我不知道如何以这种方式检查字符串的长度。任何帮助表示赞赏。

Answer 1

你的正则表达式应如下所示，你需要有关char计数器的信息

@"^(\+[0-9]{9})$"

Answer 2

Jacek 的正则表达式正常

public class Program
{
    public static void Main()
    {
        Console.WriteLine("Enter a phone number.");
        string telNo = Console.ReadLine();                      
        Console.WriteLine("{0}correctly entered", IsPhoneNumber(telNo) ? "" : "in");    
        Console.ReadLine(); 
    }

    public static bool IsPhoneNumber(string number)
    {
        return Regex.Match(number, @"^(\+[0-9]{9})$").Success;
    }
}

Answer 3

这样的事情可行：

^ + \ d {0,9}

但我建议使用正则表达式测试器来了解有关正则表达式如何工作的更多信息。我仍然喜欢自己使用它们，因为我不经常写正则表达式。这是一个例子，但还有更多的例子。

https://regex101.com/

Answer 4

不要使用正常的表达!!

正则表达式有太多变量可供使用。相反，只需删除字符串中不是0-9的所有字符，然后检查是否还有正确的位数。然后，用户包含或不包含...（）x - + []等等的额外内容并不重要，因为它只是将它们全部剥离并仅计算字符0-9。

我有一个很好的字符串扩展，并允许各种格式。它接受IsRequired参数。因此，您可以验证这样的电话号码：

string phone = "(999)999-9999"
bool isValidPhone = phone.ValidatePhoneNumber(true) // returns true

string phone ="1234567890"
bool isValidPhone = phone.ValidatePhoneNumber(true) // returns true

string phone = ""
bool isValidPhone = phone.ValidatePhoneNumber(false) // not required, so returns true

string phone = ""
bool isValidPhone = phone.ValidatePhoneNumber(true) // required, so returns false

string phone ="12345"
bool isValidPhone = phone.ValidatePhoneNumber(true) // returns false

string phone ="foobar"
bool isValidPhone = phone.ValidatePhoneNumber(true) // returns false

这里是代码（假设一个10位数的美国电话号码。相应调整）：

public static class StringExtensions
{

    /// <summary>
    /// Checks to be sure a phone number contains 10 digits as per American phone numbers.  
    /// If 'IsRequired' is true, then an empty string will return False. 
    /// If 'IsRequired' is false, then an empty string will return True.
    /// </summary>
    /// <param name="phone"></param>
    /// <param name="IsRequired"></param>
    /// <returns></returns>
    public static bool ValidatePhoneNumber(this string phone, bool IsRequired)
    {
        if (string.IsNullOrEmpty(phone) & !IsRequired)
            return true;

        if (string.IsNullOrEmpty(phone) & IsRequired)
            return false;

        var cleaned = phone.RemoveNonNumeric();
        if (IsRequired)
        {
            if (cleaned.Length == 10)
                return true;
            else
                return false;
        }
        else
        {
            if (cleaned.Length == 0)
                return true;
            else if (cleaned.Length > 0 & cleaned.Length < 10)
                return false;
            else if (cleaned.Length == 10)
                return true;
            else
                return false; // should never get here
        }
    }

    /// <summary>
    /// Removes all non numeric characters from a string
    /// </summary>
    /// <param name="phone"></param>
    /// <returns></returns>
    public static string RemoveNonNumeric(this string phone)
    {
        return Regex.Replace(phone, @"[^0-9]+", "");
    }
}

Answer 5

有效USAPhoneNumber的简单功能。

   /// <summary>
    /// Allows phone number of the format: NPA = [2-9][0-8][0-9] Nxx = [2-9]      [0-9][0-9] Station = [0-9][0-9][0-9][0-9]
    /// </summary>
    /// <param name="strPhone"></param>
    /// <returns></returns>
    public static bool IsValidUSPhoneNumber(string strPhone)
    {
        string regExPattern = @"^[01]?[- .]?(\([2-9]\d{2}\)|[2-9]\d{2})[- .]?\d{3}[- .]?\d{4}$";
        return MatchStringFromRegex(strPhone, regExPattern);
    }
    // Function which is used in IsValidUSPhoneNumber function
    public static bool MatchStringFromRegex(string str, string regexstr)
    {
        str = str.Trim();
        System.Text.RegularExpressions.Regex pattern = new System.Text.RegularExpressions.Regex(regexstr);
        return pattern.IsMatch(str);
    }

Answer 6

如果您正在寻找特定国家/地区的正则表达式，请尝试使用适用于所有澳大利亚（+ 61-）数字的表达式。我已就如何改变它用于其他用途发表评论。

public static bool IsValidPhoneNumber(string phoneNumber)
{
    //will match +61 or +61- or 0 or nothing followed by a nine digit number
    return Regex.Match(phoneNumber, 
        @"^([\+]?61[-]?|[0])?[1-9][0-9]{8}$").Success;
    //to vary this, replace 61 with an international code of your choice 
    //or remove [\+]?61[-]? if international code isn't needed
    //{8} is the number of digits in the actual phone number less one
}

Answer 7

此解决方案验证了验证电话号码的每个测试标准，它还利用了Regex API。标准包括间距，任何非数字值，区域代码（您指定），电话号码应具有的值（数字）数量，还包括错误消息以及电话号码新旧状态。

以下是源代码：

public class PhoneNumberValidator
{
    public string ErrorMessage { get; set; }
    public int PhoneNumberDigits { get; set; }
    public string CachedPhoneNumber { get; set; }

    private Dictionary<int, string> VaildAreaCodes()
    {
        return new Dictionary<int, string>
        {
            [3] = "0",
            [4] = "27"
        };
    }

    private bool IsInteger(string value)
    {
        return int.TryParse(value, out int result);
    }

    private string GetConsecutiveCharsInPhoneNumberStr(string phoneNumber)
    {
        switch (PhoneNumberDigits)
        {
            case 0:
            case 10:
                PhoneNumberDigits = 10;
                return phoneNumber.Substring(phoneNumber.Length - 7);

            case 11:
                return phoneNumber.Substring(phoneNumber.Length - 8);

            default:
                return string.Empty;
        }
    }

    private bool IsValidAreaCode(ref string phoneNumber, string areaCode)
    {
        if (!IsInteger(areaCode))
        {
            ErrorMessage = "Area code characters of Phone Number value should only contain integers.";
            return false;
        }

        var areaCodeLength = areaCode.Length;
        var invalidAreaCodeMessage = "Phone Number value contains invalid area code.";
        switch (areaCodeLength)
        {
            case 2:
                phoneNumber = string.Concat("0", phoneNumber);
                return true;

            case 3:
                if (!areaCode.StartsWith(VaildAreaCodes[3]))
                    ErrorMessage = invalidAreaCodeMessage;
                return string.IsNullOrWhiteSpace(ErrorMessage) ? true : false;

            case 4:
                if (areaCode.StartsWith(VaildAreaCodes[4]))
                {
                    phoneNumber = string.Concat("0", phoneNumber.Remove(0, 2)); // replace first two charaters with zero
                    return true;
                }                    
                ErrorMessage = invalidAreaCodeMessage;
                return false;                

            default:
                ErrorMessage = invalidAreaCodeMessage;
                return false;
        }
    }   

    public bool IsValidPhoneNumber(ref string phoneNumber)
    {
        CachedPhoneNumber = phoneNumber;

        if (string.IsNullOrWhiteSpace(phoneNumber))
        {
            ErrorMessage = "Phone Number value should not be equivalent to null.";
            return false;
        }

        phoneNumber = Regex.Replace(phoneNumber, " {2,}", string.Empty); // remove all whitespaces
        phoneNumber = Regex.Replace(phoneNumber, "[^0-9]", string.Empty); // remove all non numeric characters

        var lastConsecutiveCharsInPhoneNumberStr = GetConsecutiveCharsInPhoneNumberStr(phoneNumber);

        if (string.IsNullOrWhiteSpace(lastConsecutiveCharsInPhoneNumberStr))
        {
            ErrorMessage = "Phone Number value not supported.";
            return false;
        }

        if (!IsInteger(lastConsecutiveCharsInPhoneNumberStr))
        {
            ErrorMessage = "Last consecutive characters of Phone Number value should only contain integers.";
            return false;
        }

        var phoneNumberAreaCode = phoneNumber.Replace(lastConsecutiveCharsInPhoneNumberStr, "");

        if (!IsValidAreaCode(ref phoneNumber, phoneNumberAreaCode))
        {
            return false;
        }            

        if (phoneNumber.Length != PhoneNumberDigits)
        {
            ErrorMessage = string.Format("Phone Number value should contain {0} characters instead of {1} characters.", PhoneNumberDigits, phoneNumber.Length);
            return false;
        }

        return true;
    }
}

该解决方案具有高度可配置性，可用于任何数字电话号码和区号。

Answer 8

根据上面提供的答案之一，我想出的用于处理几种电话号码传递样式以及国际电话号码的方法是

    internal static bool IsValidPhoneNumber(this string This)
    {
        var phoneNumber = This.Trim()
            .Replace(" ", "")
            .Replace("-", "")
            .Replace("(", "")
            .Replace(")", "");
        return Regex.Match(phoneNumber, @"^\+\d{5,15}$").Success;
    }

如何验证电话号码

8 个答案: