/****************************************************************** * 創建人：HTL * 說明：C# 發送異步郵件Demo *******************************************************************/using System;using System.Net.Mail;namespace SendAsyncEmailTest{  class Program  {    const string dateFormat = "yyyy-MM-dd :HH:mm:ss:ffffff";    static void Main(string[] args)    {      Console.WriteLine("開始異步發送郵件,時間:" + DateTime.Now.ToString(dateFormat));      new MailHelper().SendAsync("Send Async Email Test", "This is Send Async Email Test", "huangyuan413026@163.com", emailCompleted);      Console.WriteLine("郵件正在異步發送,時間:" + DateTime.Now.ToString(dateFormat));      Console.ReadKey();      Console.WriteLine();    }    /// <summary>    /// 郵件發送后的回調方法    /// </summary>    /// <param name="message"></param>    static void emailCompleted(string message)    {      //延時1秒      System.Threading.Thread.Sleep(1000);      Console.WriteLine();      Console.WriteLine("郵件發送結果:/r/n" + (message == "true" ? "郵件發送成功" : "郵件發送失敗") + ",時間:" + DateTime.Now.ToString(dateFormat));      //寫入日志    }  }  /// <summary>  /// 發送郵件類  /// </summary>  public class MailHelper  {    public delegate int MethodDelegate(int x, int y);    private readonly int smtpPort = 25;    readonly string SmtpServer = "smtp.baidu.com";    private readonly string UserName = "support@baidu.com";    readonly string Pwd = "baidu.com";    private readonly string AuthorName = "BaiDu";    public string Subject { get; set; }    public string Body { get; set; }    public string Tos { get; set; }    public bool EnableSsl { get; set; }    MailMessage GetClient    {      get      {        if (string.IsNullOrEmpty(Tos)) return null;        MailMessage mailMessage = new MailMessage();        //多個接收者        foreach (string _str in Tos.Split(','))        {          mailMessage.To.Add(_str);        }        mailMessage.From = new System.Net.Mail.MailAddress(UserName, AuthorName);        mailMessage.Subject = Subject;        mailMessage.Body = Body;        mailMessage.IsBodyHtml = true;        mailMessage.BodyEncoding = System.Text.Encoding.UTF8;        mailMessage.SubjectEncoding = System.Text.Encoding.UTF8;        mailMessage.Priority = System.Net.Mail.MailPriority.High;        return mailMessage;      }    }    SmtpClient GetSmtpClient    {      get      {        return new SmtpClient        {          UseDefaultCredentials = false,          Credentials = new System.Net.NetworkCredential(UserName, Pwd),          DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network,          Host = SmtpServer,          Port = smtpPort,          EnableSsl = EnableSsl,        };      }    }    //回調方法    Action<string> actionSendCompletedCallback = null;    ///// <summary>    ///// 使用異步發送郵件    ///// </summary>    ///// <param name="subject">主題</param>    ///// <param name="body">內容</param>    ///// <param name="to">接收者,以,分隔多個接收者</param>    //// <param name="_actinCompletedCallback">郵件發送后的回調方法</param>    ///// <returns></returns>    public void SendAsync(string subject, string body, string to, Action<string> _actinCompletedCallback)    {      if (string.IsNullOrEmpty(to)) return;      Tos = to;      SmtpClient smtpClient = GetSmtpClient;      MailMessage mailMessage = GetClient;      if (smtpClient == null || mailMessage == null) return;      Subject = subject;      Body = body;      EnableSsl = false;      //發送郵件回調方法      actionSendCompletedCallback = _actinCompletedCallback;      smtpClient.SendCompleted += new SendCompletedEventHandler(SendCompletedCallback);      try      {        smtpClient.SendAsync(mailMessage, "true");//異步發送郵件,如果回調方法中參數不為"true"則表示發送失敗      }      catch (Exception e)      {        throw new Exception(e.Message);      }      finally      {        smtpClient = null;        mailMessage = null;      }    }    /// <summary>    /// 異步操作完成后執行回調方法    /// </summary>    /// <param name="sender"></param>    /// <param name="e"></param>    private void SendCompletedCallback(object sender, System.ComponentModel.AsyncCompletedEventArgs e)    {      //同一組件下不需要回調方法,直接在此寫入日志即可      //寫入日志      //return;      if (actionSendCompletedCallback == null) return;      string message = string.Empty;      if (e.Cancelled)      {        message = "異步操作取消";      }      else if (e.Error != null)      {        message = (string.Format("UserState:{0},Message:{1}", (string)e.UserState, e.Error.ToString()));      }      else        message = (string)e.UserState;      //執行回調方法      actionSendCompletedCallback(message);    }  }}