验证电子邮件地址的C#代码
验证字符串是否为有效电子邮件地址的最优雅的代码是什么?我个人认为,您应该确保其中有一个@符号,可能还有一个。性格有许多正则表达式可以使用不同的正确性,但我认为大多数都忽略了有效的电子邮件地址,或者让无效的电子邮件地址通过。如果人们想输入一个假的电子邮件地址,他们会输入一个假的。如果您需要验证电子邮件地址是否合法,以及此人是否控制该电子邮件地址,则您需要向他们发送一封带有特殊编码链接的电子邮件,以便他们能够验证该电子邮件地址是否真实。电子邮件地址验证并不像看上去那么容易。从理论上讲,仅仅使用正则表达式完全验证电子邮件地址是不可能的验证电子邮件地址的C#代码,c#,email,email-validation,C#,Email,Email Validation,验证字符串是否为有效电子邮件地址的最优雅的代码是什么?我个人认为,您应该确保其中有一个@符号,可能还有一个。性格有许多正则表达式可以使用不同的正确性,但我认为大多数都忽略了有效的电子邮件地址,或者让无效的电子邮件地址通过。如果人们想输入一个假的电子邮件地址,他们会输入一个假的。如果您需要验证电子邮件地址是否合法,以及此人是否控制该电子邮件地址,则您需要向他们发送一封带有特殊编码链接的电子邮件,以便他们能够验证该电子邮件地址是否真实。电子邮件地址验证并不像看上去那么容易。从理论上讲,仅仅使用正则表
请查看我的文章,了解关于这个主题的讨论和使用FParsec的F#实现。[/chameless\u plug]老实说,在生产代码中,我做的最好的事情就是检查
@
符号
我从来没有一个地方可以完全验证电子邮件。你知道我怎么看它是否真的有效吗?如果它被发送了。如果没有,那就糟了,如果有,生活就好了。这就是我所需要知道的。我发现这个正则表达式在检查@标记以外的内容和接受奇怪的边缘情况之间是一个很好的折衷:
^[^@\s]+@[^@\s]+(\.[^@\s]+)+$
它至少会让你在@标记周围放上一些东西,并且至少放上一个看起来正常的域。如果你真的想知道电子邮件地址是否有效……请邮件交换者证明,不需要正则表达式。如果需要,我可以提供代码 一般步骤如下: 1.电子邮件地址有域名部分吗?(指数@>0) 2.使用DNS查询询问域是否有邮件交换器 3.打开到邮件交换器的tcp连接 4.使用smtp协议,使用电子邮件地址作为收件人向服务器打开邮件 5.解析服务器的响应。 6.退出邮件如果你做到这一步,一切都很好 您可以想象,这在时间上非常昂贵,并且依赖smtp,但它确实可以工作。这是怎么回事
bool IsValidEmail(string email)
{
try {
var addr = new System.Net.Mail.MailAddress(email);
return addr.Address == email;
}
catch {
return false;
}
}
根据Stuart的评论,这会将最终地址与原始字符串进行比较,而不是总是返回true。MailAddress尝试将带有空格的字符串解析为“显示名称”和“地址”部分,因此原始版本返回的是误报
为了澄清,问题是询问特定字符串是否是电子邮件地址的有效表示形式,而不是电子邮件地址是否是发送消息的有效目的地。对于这一点,唯一真正的方法是发送消息确认 请注意,电子邮件地址比您最初设想的更宽容。这些都是完全有效的表格:
- cog@wheel
- “齿轮橙色”@example.com
- 123@$.xyz
提供健全性检查对于用户体验来说仍然是一个好主意。假设电子邮件地址有效,您可以查找已知的顶级域,检查域中的MX记录,检查常见域名(gmail.cmo)中的拼写错误,等等。然后显示警告,让用户有机会说“是的,我的邮件服务器确实允许一般来说,验证电子邮件地址的正则表达式不是一件容易的事情;在撰写本文时,电子邮件地址的语法必须遵循相当多的标准,而在正则表达式中实现所有这些标准实际上是不可行的 我强烈建议您尝试我们的,一个成熟的.NET库,它可以验证符合当前IETF标准(RFC 1123、RFC 2821、RFC 2822、RFC 3696、RFC 4291、RFC 5321和RFC 5322)的所有电子邮件地址,测试相关DNS记录,检查目标邮箱是否可以接受邮件,甚至可以判断给定地址是否为一次性地址 免责声明:我是该组件的首席开发人员。我从#1中获得了Phil的答案并创建了这个类。 这样称呼它:
bool isValid=Validator.EmailIsValid(emailString)代码>
下面是课堂:
using System.Text.RegularExpressions;
public static class Validator
{
static Regex ValidEmailRegex = CreateValidEmailRegex();
/// <summary>
/// Taken from http://haacked.com/archive/2007/08/21/i-knew-how-to-validate-an-email-address-until-i.aspx
/// </summary>
/// <returns></returns>
private static Regex CreateValidEmailRegex()
{
string validEmailPattern = @"^(?!\.)(""([^""\r\\]|\\[""\r\\])*""|"
+ @"([-a-z0-9!#$%&'*+/=?^_`{|}~]|(?<!\.)\.)*)(?<!\.)"
+ @"@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$";
return new Regex(validEmailPattern, RegexOptions.IgnoreCase);
}
internal static bool EmailIsValid(string emailAddress)
{
bool isValid = ValidEmailRegex.IsMatch(emailAddress);
return isValid;
}
}
使用System.Text.regular表达式;
公共静态类验证器
{
静态正则表达式ValidEmailRegex=CreateValidEmailRegex();
///
///取自http://haacked.com/archive/2007/08/21/i-knew-how-to-validate-an-email-address-until-i.aspx
///
///
私有静态正则表达式createValidMailRegex()
{
字符串ValidMailPattern=@“^(?!\)(“”([^”“\r\\]\\\\\[”“\r\\])*“”
+@“([-a-z0-9!#$%&'*+/=?^ `{124}~])(?这是一个老问题,但我在上面找到的所有答案,包括最近的答案,都与此类似。然而,在.Net 4.5/MVC 4中,您可以通过添加[EmailAddress]将电子邮件地址验证添加到表单中来自System.ComponentModel.DataAnnotations的注释,所以我想知道为什么我不能一般使用.Net中的内置功能
这似乎有效,而且在我看来相当优雅:
using System.ComponentModel.DataAnnotations;
class ValidateSomeEmails
{
static void Main(string[] args)
{
var foo = new EmailAddressAttribute();
bool bar;
bar = foo.IsValid("someone@somewhere.com"); //true
bar = foo.IsValid("someone@somewhere.co.uk"); //true
bar = foo.IsValid("someone+tag@somewhere.net"); //true
bar = foo.IsValid("futureTLD@somewhere.fooo"); //true
bar = foo.IsValid("fdsa"); //false
bar = foo.IsValid("fdsa@"); //false
bar = foo.IsValid("fdsa@fdsa"); //false
bar = foo.IsValid("fdsa@fdsa."); //false
//one-liner
if (new EmailAddressAttribute().IsValid("someone@somewhere.com"))
bar = true;
}
}
我认为最好的办法如下:
public static bool EmailIsValid(string email)
{
string expression = "\\w+([-+.']\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*";
if (Regex.IsMatch(email, expression))
{
if (Regex.Replace(email, expression, string.Empty).Length == 0)
{
return true;
}
}
return false;
}
您可以在常规类中使用此静态函数。.net 4.5已添加
您可以浏览,这是它内部使用的正则表达式:
const string pattern = @"^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?$";
下面是我的答案--Phil的解决方案对于单字母域失败,如“someone@q.com“。信不信由你,这是用过的=)(例如,转到centurylink)
Phil的答案也只适用于PCRE标准…所以C#会接受它,但javascript会爆炸。它对javascript来说太复杂了。所以你不能使用Phil的解决方案进行mvc验证属性
这是我的正则表达式,它可以很好地与
public const string EmailPattern =
@"^\s*[\w\-\+_']+(\.[\w\-\+_']+)*\@[A-Za-z0-9]([\w\.-]*[A-Za-z0-9])?\.[A-Za-z][A-Za-z\.]*[A-Za-z]$";
private static bool IsValidEmail(string emailAddress)
{
const string validEmailPattern = @"^(?!\.)(""([^""\r\\]|\\[""\r\\])*""|"
+ @"([-a-z0-9!#$%&'*+/=?^_`{|}~]|(?<!\.)\.)*)(?<!\.)"
+ @"@[a-z0-9][\w\.-]*[a-z0-9]\.[a-z][a-z\.]*[a-z]$";
return new Regex(validEmailPattern, RegexOptions.IgnoreCase).IsMatch(emailAddress);
}
public static bool IsValidEmailId(string InputEmail)
{
Regex regex = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$");
Match match = regex.Match(InputEmail);
if (match.Success)
return true;
else
return false;
}
protected void Email_TextChanged(object sender, EventArgs e)
{
String UserEmail = Email.Text;
if (IsValidEmailId(UserEmail))
{
Label4.Text = "This email is correct formate";
}
else
{
Label4.Text = "This email isn't correct formate";
}
}
public bool IsEmail(string email)
{
if (String.IsNullOrEmpty(email))
{ return false; }
try
{
Regex _regex = new Regex("^((([a-z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])" +
"+(\\.([a-z]|\\d|[!#\\$%&'\\*\\+\\-\\/=\\?\\^_`{\\|}~]|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])+)*)|((\\x22)" +
"((((\\x20|\\x09)*(\\x0d\\x0a))?(\\x20|\\x09)+)?(([\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x7f]|\\x21|[\\x23-\\x5b]|[\\x5d-\\x7e]|" +
"[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])|(\\\\([\\x01-\\x09\\x0b\\x0c\\x0d-\\x7f]|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\u" +
"FDF0-\\uFFEF]))))*(((\\x20|\\x09)*(\\x0d\\x0a))?(\\x20|\\x09)+)?(\\x22)))@((([a-z]|\\d|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])|" +
"(([a-z]|\\d|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])([a-z]|\\d|-|\\.|_|~|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])*([a-z]|\\d|" +
"[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])))\\.)+(([a-z]|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])|(([a-z]|[\\u00A0-\\uD7FF\\uF900" +
"-\\uFDCF\\uFDF0-\\uFFEF])([a-z]|\\d|-|\\.|_|~|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFFEF])*([a-z]|[\\u00A0-\\uD7FF\\uF900-\\uFDCF\\uFDF0-\\uFF" +
"EF])))\\.?$", RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture | RegexOptions.Compiled);
return _regex.IsMatch(email);
}
catch (RegexMatchTimeoutException)
{
return false;
}
}
using System.ComponentModel.DataAnnotations;
public bool IsValidEmail(string source)
{
return new EmailAddressAttribute().IsValid(source);
}
public static bool IsValidEmailAddress(this string address) => address != null && new EmailAddressAttribute().IsValid(address);
public static bool IsValidEmailAddress(string candidateEmailAddr)
{
string regexExpresion = "\\w+([-+.']\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*";
return (Regex.IsMatch(candidateEmailAddr, regexExpresion)) &&
(Regex.Replace(candidateEmailAddr, regexExpresion, string.Empty).Length == 0);
}
(new EmailAddressAttribute().IsValid("youremailhere@test.test"));
protected List<string> GetRecipients() // Gets recipients from TextBox named `TxtRecipients`
{
List<string> MethodResult = null;
try
{
List<string> Recipients = TxtRecipients.Text.Replace(",",";").Replace(" ", "").Split(';').ToList();
List<string> RecipientsCleaned = new List<string>();
foreach (string Recipient in RecipientsCleaned)
{
if (!String.IsNullOrWhiteSpace(Recipient))
{
RecipientsNoBlanks.Add(Recipient);
}
}
MethodResult = RecipientsNoBlanks;
}
catch//(Exception ex)
{
//ex.HandleException();
}
return MethodResult;
}
public static bool IsValidEmailAddresses(List<string> recipients)
{
List<string> InvalidAddresses = GetInvalidEmailAddresses(recipients);
return InvalidAddresses != null && InvalidAddresses.Count == 0;
}
public static List<string> GetInvalidEmailAddresses(List<string> recipients)
{
List<string> MethodResult = null;
try
{
List<string> InvalidEmailAddresses = new List<string>();
foreach (string Recipient in recipients)
{
if (!(new EmailAddressAttribute().IsValid(Recipient)) && !InvalidEmailAddresses.Contains(Recipient))
{
InvalidEmailAddresses.Add(Recipient);
}
}
MethodResult = InvalidEmailAddresses;
}
catch//(Exception ex)
{
//ex.HandleException();
}
return MethodResult;
}
List<string> Recipients = GetRecipients();
bool IsValidEmailAddresses = IsValidEmailAddresses(Recipients);
if (IsValidEmailAddresses)
{
//Emails are valid. Your code here
}
else
{
StringBuilder sb = new StringBuilder();
sb.Append("The following addresses are invalid:");
List<string> InvalidEmails = GetInvalidEmailAddresses(Recipients);
foreach (string InvalidEmail in InvalidEmails)
{
sb.Append("\n" + InvalidEmail);
}
MessageBox.Show(sb.ToString());
}
public static bool IsValidEmailAddress(string emailAddress)
{
bool MethodResult = false;
try
{
MailAddress m = new MailAddress(emailAddress);
MethodResult = m.Address == emailAddress;
}
catch //(Exception ex)
{
//ex.HandleException();
}
return MethodResult;
}
public static List<string> GetInvalidEmailAddresses(List<string> recipients)
{
List<string> MethodResult = null;
try
{
List<string> InvalidEmailAddresses = new List<string>();
foreach (string Recipient in recipients)
{
if (!IsValidEmail(Recipient) && !InvalidEmailAddresses.Contains(Recipient))
{
InvalidEmailAddresses.Add(Recipient);
}
}
MethodResult = InvalidEmailAddresses;
}
catch //(Exception ex)
{
//ex.HandleException();
}
return MethodResult;
}
using System;
using System.Globalization;
using System.Text.RegularExpressions;
public class RegexUtilities
{
public bool IsValidEmail(string strIn)
{
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][\-a-z0-9]{0,22}[a-z0-9]))$", 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;
}
}
public static bool EmailIsValid(string email)
{
return Regex.IsMatch(email, @"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$");
}
Regex.IsMatch(email, @"^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9_\-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$", RegexOptions.ECMAScript)
public const string REGEX_EMAIL = @"^(((\([\w!#$%&'*+\/=?^_`{|}~-]*\))?[^<>()[\]\\.,;:\s@\""]+(\.[^<>()[\]\\.,;:\s@\""]+)*)|(\"".+\""))(\([\w!#$%&'*+\/=?^_`{|}~-]*\))?@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$";
bool IsValidEmail(string email)
{
string emailTrimed = email.Trim();
if (!string.IsNullOrEmpty(emailTrimed))
{
bool hasWhitespace = emailTrimed.Contains(" ");
int indexOfAtSign = emailTrimed.LastIndexOf('@');
if (indexOfAtSign > 0 && !hasWhitespace)
{
string afterAtSign = emailTrimed.Substring(indexOfAtSign + 1);
int indexOfDotAfterAtSign = afterAtSign.LastIndexOf('.');
if (indexOfDotAfterAtSign > 0 && afterAtSign.Substring(indexOfDotAfterAtSign).Length > 1)
return true;
}
}
return false;
}
For the simple email like goerge@xxx.com, below code is sufficient.
public static bool ValidateEmail(string email)
{
System.Text.RegularExpressions.Regex emailRegex = new System.Text.RegularExpressions.Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$");
System.Text.RegularExpressions.Match emailMatch = emailRegex.Match(email);
return emailMatch.Success;
}
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);
}
public cass User
{
public string Email { get; set; }
}
public class UserValidator : AbstractValidator<User>
{
public UserValidator()
{
RuleFor(x => x.Email).EmailAddress().WithMessage("The text entered is not a valid email address.");
}
}
// Validates an user.
var validationResult = new UserValidator().Validate(new User { Email = "açflkdj" });
// This will return false, since the user email is not valid.
bool userIsValid = validationResult.IsValid;
public static bool IsValidEmail(this string email)
{
// skip the exception & return early if possible
if (email.IndexOf("@") <= 0) return false;
try
{
var address = new MailAddress(email);
return address.Address == email;
}
catch
{
return false;
}
}
public static bool IsEmail(this string input)
{
if (string.IsNullOrWhiteSpace(input)) return false;
// MUST CONTAIN ONE AND ONLY ONE @
var atCount = input.Count(c => c == '@');
if (atCount != 1) return false;
// MUST CONTAIN PERIOD
if (!input.Contains(".")) return false;
// @ MUST OCCUR BEFORE LAST PERIOD
var indexOfAt = input.IndexOf("@", StringComparison.Ordinal);
var lastIndexOfPeriod = input.LastIndexOf(".", StringComparison.Ordinal);
var atBeforeLastPeriod = lastIndexOfPeriod > indexOfAt;
if (!atBeforeLastPeriod) return false;
// CODE FROM COGWHEEL'S ANSWER: https://stackoverflow.com/a/1374644/388267
try
{
var addr = new System.Net.Mail.MailAddress(input);
return addr.Address == input;
}
catch
{
return false;
}
}
bool IsValidEmail(string email)
{
try
{
email = email.Trim();
var addr = new System.Net.Mail.MailAddress(email);
return addr.Address == email;
}
catch
{
return false;
}
}
// Valid: david.jones@proseware.com
// Valid: d.j@server1.proseware.com
// Valid: jones@ms1.proseware.com
// Invalid: j.@server1.proseware.com
// Valid: j@proseware.com9
// Valid: js#internal@proseware.com
// Valid: j_9@[129.126.118.1]
// Invalid: j..s@proseware.com
// Invalid: js*@proseware.com
// Invalid: js@proseware..com
// Valid: js@proseware.com9
// Valid: j.s@server1.proseware.com
// Valid: "j\"s\""@proseware.com
// Valid: js@contoso.中国