使用正则表达式的电子邮件验证

    string pattern = @"\A(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?)\Z";

    //check first string
   if (Regex.IsMatch(EmailId1 , pattern))
   {    
       //if email is valid
        Console.WriteLine(EmailId1+ " is a valid Email address ");
   }

来源:电子邮件验证c#

使用MailAddress.MailAddress(String)类构造函数没有Regex的验证

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

为什么不使用基于EF6属性的电子邮件验证?

正如您在上面所看到的，电子邮件的Regex验证总是有一些漏洞。如果您使用的是EF6数据注释，则可以通过EmailAddress数据注释属性轻松实现可靠且更强的电子邮件验证。当我在电子邮件输入字段上获得移动设备特定的正则表达式失败时，我不得不删除以前用于电子邮件的正则表达式验证。当数据注释属性用于电子邮件验证时，移动设备上的问题就解决了。

public class LoginViewModel
{
    [EmailAddress(ErrorMessage = "The email format is not valid")]
    public string Email{ get; set; }

没有完美的正则表达式，但我认为，基于对RFC5322的研究，这个正则表达式相当强大。用c#字符串插值，我认为也很容易理解。

const string atext = @"a-zA-Z\d!#\$%&'\*\+-/=\?\^_`\{\|\}~";
var localPart = $"[{atext}]+(\\.[{atext}]+)*";
var domain = $"[{atext}]+(\\.[{atext}]+)*";
Assert.That(() => EmailRegex = new Regex($"^{localPart}@{domain}$", Compiled), 
Throws.Nothing);

用NUnit 2.x检查。

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;

}

我使用:

public bool ValidateEmail(string email)
{
   Regex regex = new Regex("^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$");
   if (regex.IsMatch(email))
      return true;

     return false;
}

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));
    }
}