电子邮件地址验证

Question

所以我要做的是验证用户将自己输入的电子邮件地址。

微软开发者网络在以下链接中提供了如何验证电子邮件地址的示例代码：http://msdn.microsoft.com/en-us/library/01escwtf(v=vs.110).aspx

无论如何，我只是复制了代码并尝试使用它。但是我不断收到此错误：

The type or namespace name 'IdnMapping' could not be found (are you missing a using directive or an assembly reference?)

我在网上找不到任何类似的问题，我想不出会导致此错误的原因。

当然，当我们看到这样的错误时，首先想到的是我们忘记包含某些内容。

但是，我在上面的页面中包含了所需的任何内容，并且将在我的代码中显示。所以我什至无法理解问题本身的性质，无法开始寻找可能的解决方案。

我的代码：

using System;
using System.Globalization;
using System.Text.RegularExpressions;

public bool IsValidEmail(string strIn)
    {
        bool invalid = false;
        if (String.IsNullOrEmpty(strIn))
            return false;

        // Use IdnMapping class to convert Unicode domain names. 
        try
        {
            strIn = Regex.Replace(strIn, @"(@)(.+)$", this.DomainMapper,
                                  RegexOptions.None, TimeSpan.FromMilliseconds(200));
        }
        catch (RegexMatchTimeoutException)
        {
            return false;
        }

        if (invalid)
            return false;

        // Return true if strIn is in valid e-mail format. 
        try
        {
            return Regex.IsMatch(strIn,
                  @"^(?("")(""[^""]+?""@)|(([0-9a-z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-z])@))" +
                  @"(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-z][-\w]*[0-9a-z]*\.)+[a-z0-9]{2,24}))$",
                  RegexOptions.IgnoreCase, TimeSpan.FromMilliseconds(250));
        }
        catch (RegexMatchTimeoutException)
        {
            return false;
        }
    }

    private string DomainMapper(Match match)
    {
        // IdnMapping class with default property values.
        IdnMapping idn = new IdnMapping();

        string domainName = match.Groups[2].Value;
        try
        {
            domainName = idn.GetAscii(domainName);
        }
        catch (ArgumentException)
        {
            invalid = true;
        }
        return match.Groups[1].Value + domainName;
    }

有关如何解决此问题或至少了解问题性质的任何建议。 在此先感谢:)

Answer 1

.NET for Windows Phone 上似乎不存在该类。

This MSDN page 表示它仅存在于 .NET Framework 2.0+ 和 .NET Framework Client Profile 3.5 SP1+。

Answer 2

试试这个符合 RFC822 的方法：

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?:\r\n)?[ \t])*))*)?;\s*)".Replace(Environment.NewLine, "");

那么你可以这样做：

    var emailRegex = new Regex(text);

    var isValid = emailRegex.IsMatch("foo@bar.com");

说真的，这是正确的。

Answer 3

使用 MailAddress 类，这是一段不错的代码。 原因是其他人已经为您完成了 Regex。

    public bool IsValid(string emailaddress)
    {
        try
        {
            MailAddress m = new MailAddress(emailaddress);
            return true;
        }
        catch (FormatException)
        {
            return false;
        }
    }

Answer 4

好的，我现在才找到这个，它似乎对我有用，我只是想分享它。

private bool IsValidEmail(string emailAddress)
{
        // Return true if emailAddress is in valid e-mail format.
        return Regex.IsMatch(emailAddress, @"^([0-9a-zA-Z]([-\.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9})$");
}