代碼寫在Global.aszx中，系統(tǒng)自動(dòng)運(yùn)行

1.Application_Start（）中設(shè)定一個(gè)定時(shí)器以及郵件發(fā)送事件

 protected void Application_Start(object sender, EventArgs e)
        {
            System.Timers.Timer timer = new System.Timers.Timer(30000);
            timer.Elapsed += new System.Timers.ElapsedEventHandler(Send);
            timer.Start();
        }

2.對Send()方法進(jìn)行編輯，設(shè)定發(fā)送的時(shí)間、發(fā)送郵箱和接收郵箱

 public void Send(object sender, System.Timers.ElapsedEventArgs e)
        {
            SqlConnection myconn = new SqlConnection("Data Source=100.0.4.51;Initial Catalog=XRX;User ID=xrx;Password=b879d~c2a81fd#9b8e33@ffd5!85e5c6cfb9");          
            string sql = "select mail from MailTest";
            SqlCommand mycmd = new SqlCommand(sql, myconn);
            if (myconn.State == ConnectionState.Closed)
            {
                myconn.Open();
            }
            SqlDataReader reader = mycmd.ExecuteReader();


            SqlConnection myconn2 = new SqlConnection("Data Source=100.0.4.51;Initial Catalog=XRX;User ID=xrx;Password=b879d~c2a81fd#9b8e33@ffd5!85e5c6cfb9");
            myconn2.Open();
            string sql2 = "select Student.StuID,Student.StuName,Course.CourseName,StudentSign.SignState,StudentSign.OutState, StudentSign.LeaveState,StudentSign.ReMark,StudentSign.LateState from StudentSign join Schedule on Schedule.ScheduleID = StudentSign.ScheduleID join Student on Student.ID = StudentSign.StuID join Course on Course.ID = Schedule.CourseID group by Student.StuID,Student.StuName,Course.CourseName,StudentSign.SignState, StudentSign.OutState,StudentSign.LeaveState,StudentSign.ReMark,StudentSign.LateState";
            SqlCommand mycmd2 = new SqlCommand(sql2, myconn2);                            
            SqlDataReader reader2 = mycmd2.ExecuteReader();
            List<string> record = new List<string>();
            while (reader2.Read())
            {
                string msg = "<td>"+reader2["StuID"].ToString() + "</td><td>" + reader2["StuName"].ToString() + "</td><td>" + reader2["CourseName"].ToString() + "</td><td>" + reader2["SignState"].ToString() + "</td><td>" + reader2["OutState"].ToString() + "</td><td>" + reader2["LeaveState"].ToString() + "</td><td>" + reader2["Remark"].ToString() + "</td><td>" + reader2["LateState"].ToString() + "</td>";
                record.Add(msg);
            }
            myconn2.Close();


            if (DateTime.Now.Minute == 10)
            {
                string mailBody = getMailBody(record);
                while (reader.Read())
                {
                    string aMail = reader["mail"].ToString();
                    //string msg = reader2["StuID"].ToString() +"  "+ reader2["StuName"].ToString() +"  "+ reader2["CourseName"].ToString() + "  " + reader2["SignState"].ToString() + "  " + reader2["OutState"].ToString();
                    SendEMail("'" + aMail + "'", "'" + aMail + "'", "考勤信息統(tǒng)計(jì)", "" + mailBody + "");
                }
                //endEMail sm = new SendMail();
                //SendEMail("'"+sql+"'", "'" + sql + "'", "Auto Mail", "This is a auto amil!");
            }
            myconn.Close();          
        }

3.生成讀取郵件內(nèi)容的方法，創(chuàng)建StringBuilder類

 private string getMailBody(List<String> list)
        {
            StringBuilder result = new StringBuilder();
            result.Append("<table><tr><td>學(xué)號</td><td>姓名</td><td>課程</td><td>簽到狀態(tài)</td><td>簽退狀態(tài)                                         </td><td>請假</td><td>標(biāo)記</td><td>遲到</td></tr>");
            foreach (string aStr in list){                
                result.Append("<tr>").Append(aStr).Append("</tr>");
            }
            result.Append("</table>");
            return result.ToString();

        }

3.設(shè)定郵件發(fā)送時(shí)間，讀取郵件地址和內(nèi)容

  if (DateTime.Now.Minute == 10)
            {
                string mailBody = getMailBody(record);
                while (reader.Read())
                {
                    string aMail = reader["mail"].ToString();
                    SendEMail("'" + aMail + "'", "'" + aMail + "'", "考勤信息統(tǒng)計(jì)", "" + mailBody + "");
                }             
            }

            myconn.Close();    

DataTime.Now. xx  可以按照自己的需求去選擇發(fā)送郵件的間隔

3.對SendEmail()方法進(jìn)行編寫

 public void SendEMail(string To1, string CC1, /*string BC1,*/ string Subject1, string Body1)
        {
            MailMessage msg = new MailMessage("xxxx@qq.com", To1);
            msg.CC.Add(CC1);
            //msg.Bcc.Add(BC1);
            msg.Subject = Subject1;
            msg.Body = Body1;
            msg.IsBodyHtml = true;
            msg.Priority = MailPriority.High;//發(fā)送郵件的優(yōu)先等級 
            SmtpClient c = new SmtpClient("smtp.qq.com", 587);
            System.Net.NetworkCredential basicAuthenticationInfo =
               new System.Net.NetworkCredential("xxxxx@qq.com", "xxxxxx");//用戶名與SMTP授權(quán)碼
            c.Credentials = basicAuthenticationInfo;
            c.EnableSsl = true;//啟用SSL加密 
            //c.Port = 587;
            c.Send(msg);
        }

4.新建一個(gè)web窗體，運(yùn)行程序