验证字符串是否是有效的电子邮件地址的最优雅的代码是什么?


当前回答

我用的是单线法,它对我有用

using System.ComponentModel.DataAnnotations;
public bool IsValidEmail(string source)
{
    return new EmailAddressAttribute().IsValid(source);
}

根据注释,如果源(电子邮件地址)为空,这将“失败”。

public static bool IsValidEmailAddress(this string address) => address != null && new EmailAddressAttribute().IsValid(address);

其他回答

这是一个老问题,但我在SO上找到的所有答案,包括最近的答案,都与这个问题类似。然而,在。net 4.5 / MVC 4中,你可以通过从System.ComponentModel中添加[EmailAddress]注释来向表单添加电子邮件地址验证。DataAnnotations,所以我想知道为什么我不能只使用。net的内置功能。

这似乎是可行的,而且在我看来是相当优雅的:

using System.ComponentModel.DataAnnotations;

class ValidateSomeEmails
{
    static void Main(string[] args)
    {
        var email = new EmailAddressAttribute();
        email.IsValid("someone@somewhere.com");         //true
        email.IsValid("someone@somewhere.co.uk");       //true
        email.IsValid("someone+tag@somewhere.net");     //true
        email.IsValid("futureTLD@somewhere.fooo");      //true
        
        email.IsValid("fdsa");                          //false
        email.IsValid("fdsa@");                         //false
        email.IsValid("fdsa@fdsa");                     //false
        email.IsValid("fdsa@fdsa.");                    //false

        //one-liner
        if (new EmailAddressAttribute().IsValid("someone@somewhere.com")) 
            return true;
    }
}

短而准确的代码

string Email = txtEmail.Text;
if (Email.IsValidEmail())
{
   //use code here 
}

public static bool IsValidEmail(this string email)
{
  string pattern = @"^(?!\.)(""([^""\r\\]|\\[""\r\\])*""|" + @"([-a-z0-9!#$%&'*+/=?^_`{|}~]|(?<!\.)\.)*)(?<!\.)" + @"@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$";    
  var regex = new Regex(pattern, RegexOptions.IgnoreCase);    
  return regex.IsMatch(email);
}

我总结了以上所有的答案,截至2021年,我在这门课上为自己写的答案:

public static class StringExt {
    private const string emailPattern = @"^(?!\.)(""([^""\r\\]|\\[""\r\\])*""|" 
            + @"([-a-z0-9!#$%&'*+/=?^_`{|}~]|(?<!\.)\.)*)(?<!\.)" 
            + @"@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$";

    public static bool IsValidMailAddress(this string pThis) 
            => pThis is not null 
            && Regex.IsMatch(pThis, emailPattern, RegexOptions.IgnoreCase);
}
For the simple email like goerge@xxx.com, below code is sufficient. 

 public static bool ValidateEmail(string email)
        {
            System.Text.RegularExpressions.Regex emailRegex = new System.Text.RegularExpressions.Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$");
            System.Text.RegularExpressions.Match emailMatch = emailRegex.Match(email);
            return emailMatch.Success;
        }

基于@Cogwheel的回答,我想分享一个修改后的解决方案,适用于SSIS和“脚本组件”:

Place the "Script Component" into your Data Flow connect and then open it. In the section "Input Columns" set the field that contains the E-Mail Adresses to "ReadWrite" (in the example 'fieldName'). Switch back to the section "Script" and click on "Edit Script". Then you need to wait after the code opens. Place this code in the right method: public override void Input0_ProcessInputRow(Input0Buffer Row) { string email = Row.fieldName; try { System.Net.Mail.MailAddress addr = new System.Net.Mail.MailAddress(email); Row.fieldName= addr.Address.ToString(); } catch { Row.fieldName = "WRONGADDRESS"; } }

然后,您可以使用条件分割过滤掉所有无效记录或任何您想做的事情。