介绍
System.Net.Mail命名空间是在.NET Framework中新增的，该命名空间提供了发送电子邮件的功能。通过对本章的学习，读者可以轻松地使用.NET Framework提供的类库来发送电子邮件。System.Net.Mail 命名空间包含用于将电子邮件发送到SMTP服务器的类，这些类需要结合Microsoft SMTP Server一起使用。
System.Net.Mail 命名空间下有SmtpClient类用于发送邮件，可以完全代替SmtpMail类。利用SmtpClient类的Send方法可以完成发送电子邮件的传 输，也可以用SendAsync方法进行异步发送，后者发送完成后会产生一个SendCompleted 事件来通知发送结果。Send方法可以接受MailMessage类的对象作为参数。通过MailMessage类可以设置邮件更多的内容和格式，例如，为 Attachment类设置添加附件的参数。
SmtpClient 类与SMTP结合在一起，通过MailMessage类、MailAddress类、Attachment类来丰富电子邮件的内容和设置。图18-2展示 了用户通过System.Net.Mail命名空间下的类结合SMTP发送电子邮件的过程。
SmtpClient类的语法定义如下：
public class SmtpClient
下面的代码演示如何创 建一个SmtpClient的实例。
SmtpClient client = new SmtpClient (“smtp.Sina.com”); //直接通过构造函数设置SMTP 主机服务器
或：
SmtpClient client = new SmtpClient ();
Client. Host =” smtp.Sina.com”; //通过Host属性来设置SMTP 主机服务器
完整代码
/// <summary>/// 邮件处理器/// </summary>public class MailHandler{private MailMessage _mailMessage;private string _host;private string _userName;private string _password;public MailHandler(){}/// <summary>/// 设置邮件信息/// </summary>/// <param name="subject">主体</param>/// <param name="body">内容</param>/// <param name="from">发件人</param>/// <param name="to">收件人</param>/// <param name="cc">抄送人</param>/// <param name="bcc">密件抄送人</param>/// <param name="isBodyHtml">内容是否为Html</param>public void SetMailMessage(string subject, string body, string from, string[] to, string[] cc, string[] bcc, bool isBodyHtml = true){_mailMessage = new MailMessage();_mailMessage.Subject = subject;_mailMessage.Body = body;_mailMessage.IsBodyHtml = isBodyHtml;_mailMessage.From = new MailAddress(from);if (to != null){foreach (var item in to){_mailMessage.To.Add(item);}}if (cc != null){foreach (var item in cc){_mailMessage.CC.Add(item);}}if (bcc != null){foreach (var item in bcc){_mailMessage.Bcc.Add(item);}}_mailMessage.BodyEncoding = System.Text.Encoding.UTF8;}/// <summary>/// 配置Smtp服务主机及身份验证/// </summary>/// <param name="host">Smtp主机名或Ip</param>/// <param name="userName">用户名</param>/// <param name="password">密码</param>public void SetSmtp(string host, string userName, string password){this._host = host;this._userName = userName;this._password = password;}/// <summary>/// 发送邮件/// </summary>public void Send(){using (var sc = new SmtpClient()){sc.Host = _host;sc.Port = 25;sc.DeliveryMethod = SmtpDeliveryMethod.Network;sc.Credentials = new System.Net.NetworkCredential(_userName, _password);sc.Send(_mailMessage);}}public string SendMail(string title, string content){var smptHost = ConfigHelper.GetAppSetting("SmtpHost");var userName = ConfigHelper.GetAppSetting("MailUserName");var password = ConfigHelper.GetAppSetting("MailPassword");var mailToAddress = ConfigHelper.GetAppSetting("MailAddress").Split(',');if (string.IsNullOrWhiteSpace(smptHost)){return "SmtpHost为空";}if (string.IsNullOrWhiteSpace(userName)){return "发件人为空";}if (string.IsNullOrWhiteSpace(password)){return "发件人密码为空";}if (mailToAddress.Length == 0){return "收件人列表为空";}var mailContent = @"<html><head><title>邮件内容</title></head><body>" + content + "</body></html>";SetSmtp(smptHost, userName, password);SetMailMessage(title, mailContent, userName, mailToAddress, null, null);try{Send();}catch (Exception ex){return ex.Message;}return null;}}
)
