这是目前为止我最喜欢的方法:

public static class CommonExtensions
{
    public static bool IsValidEmail(this string thisEmail)
        => !string.IsNullOrWhiteSpace(thisEmail) &&
           new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$").IsMatch(thisEmail);
}

然后使用创建的字符串扩展名，如:

if (!emailAsString.IsValidEmail()) throw new Exception("Invalid Email");

如果它不起作用，请告诉我:)

public static bool isValidEmail(this string email)
{

    string[] mail = email.Split(new string[] { "@" }, StringSplitOptions.None);

    if (mail.Length != 2)
        return false;

    //check part before ...@

    if (mail[0].Length < 1)
        return false;

    System.Text.RegularExpressions.Regex regex = new System.Text.RegularExpressions.Regex(@"^[a-zA-Z0-9_\-\.]+$");
    if (!regex.IsMatch(mail[0]))
        return false;

    //check part after @...

    string[] domain = mail[1].Split(new string[] { "." }, StringSplitOptions.None);

    if (domain.Length < 2)
        return false;

    regex = new System.Text.RegularExpressions.Regex(@"^[a-zA-Z0-9_\-]+$");

    foreach (string d in domain)
    {
        if (!regex.IsMatch(d))
            return false;
    }

    //get TLD
    if (domain[domain.Length - 1].Length < 2)
        return false;

    return true;

}

我创建了一个FormValidationUtils类来验证电子邮件:

public static class FormValidationUtils
{
    const string ValidEmailAddressPattern = "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,6}$";

    public static bool IsEmailValid(string email)
    {
        var regex = new Regex(ValidEmailAddressPattern, RegexOptions.IgnoreCase);
        return regex.IsMatch(email);
    }
}

我在MSDN上找到了一个很好的文档。

如何:验证字符串是否在有效的电子邮件格式 http://msdn.microsoft.com/en-us/library/01escwtf.aspx (请注意，这段代码还支持在Internet域名中使用非ascii字符。)

有两个实现，用于。net 2.0/3.0和用于。net 3.5及更高版本。 2.0/3.0版本为:

bool IsValidEmail(string strIn)
{
    // Return true if strIn is in valid e-mail format.
    return Regex.IsMatch(strIn, @"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$"); 
}

我对这个方法的测试给出:

Invalid: @majjf.com
Invalid: A@b@c@example.com
Invalid: Abc.example.com
Valid: j..s@proseware.com
Valid: j.@server1.proseware.com
Invalid: js*@proseware.com
Invalid: js@proseware..com
Valid: ma...ma@jjf.co
Valid: ma.@jjf.com
Invalid: ma@@jjf.com
Invalid: ma@jjf.
Invalid: ma@jjf..com
Invalid: ma@jjf.c
Invalid: ma_@jjf
Invalid: ma_@jjf.
Valid: ma_@jjf.com
Invalid: -------
Valid: 12@hostname.com
Valid: d.j@server1.proseware.com
Valid: david.jones@proseware.com
Valid: j.s@server1.proseware.com
Invalid: j@proseware.com9
Valid: j_9@[129.126.118.1]
Valid: jones@ms1.proseware.com
Invalid: js#internal@proseware.com
Invalid: js@proseware.com9
Invalid: js@proseware.com9
Valid: m.a@hostname.co
Valid: m_a1a@hostname.com
Valid: ma.h.saraf.onemore@hostname.com.edu
Valid: ma@hostname.com
Invalid: ma@hostname.comcom
Invalid: MA@hostname.coMCom
Valid: ma12@hostname.com
Valid: ma-a.aa@hostname.com.edu
Valid: ma-a@hostname.com
Valid: ma-a@hostname.com.edu
Valid: ma-a@1hostname.com
Valid: ma.a@1hostname.com
Valid: ma@1hostname.com

我认为你的插入符号和美元符号是问题的一部分 你也应该修改一下正则表达式，我用的是下一个 @"[ :]+([\ w -] +) @ ((\ w -.])+((.(\ w){2,3}) +)”

以下是我从这里收集信息和微软文档后的解决方案:

/// <summary>
/// * TLD support from 2 to 5 chars (modify the values as you want)
/// * Supports: abc@gmail.com.us
/// * Non-sensitive case 
/// * Stops operation if takes longer than 250ms and throw a detailed exception
/// </summary>
/// <param name="email"></param>
/// <returns>valid: true | invalid: false </returns>
/// <exception cref="ArgumentException"></exception>

private bool validateEmailPattern(string email) {
    try {
        return Regex.IsMatch(email,
            @"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,5})+)$",
            RegexOptions.None, TimeSpan.FromMilliseconds(250));
    } catch (RegexMatchTimeoutException) {
        // throw an exception explaining the task was failed 
        _ = email ?? throw new ArgumentException("email, Timeout/failed regexr processing.", nameof(email));
    }
}