1 获得用户数据
2    验证 非空、格式
3    验证 图形验证码
4    判断 用户是否存在，需要不存在
5    判断 邮箱是否已激活使用，需要未激活
6    向DB中插入用户，未激活（只要插入，无论激活否，先存入session，如果失败可以用到）
7    发送邮件username,activecode，并存入session,设置有效日期
8    返回激活码，如果激活码正确，更新DB中激活码
9    返回“注册并激活成功，跳转首页”，否则返回“注册成功但激活失败，重新激活新邮箱”
10    [重新激活邮箱：如果新邮箱未激活使用，则发送激活码，如果返回正确，更新当前用户邮箱并激活
11    返回“激活成功，跳转首页”]

    public class SendEmailHelper{/// <summary>/// 发送邮件/// </summary>/// <param name="receiveEmailAddress">接收方邮箱地址</param>/// <param name="subject">邮件主题</param>/// <param name="body">邮件内容</param>public static void SendMail(string receiveEmailAddress,string subject,string body){string sendEmailUserName = ConfigurationManager.AppSettings["sendEmailUserName"]; //发送方邮箱登录名string sendEmaiPassword = ConfigurationManager.AppSettings["sendEmaiPassword"]; //发送方邮箱密码string sendEmailAddress = ConfigurationManager.AppSettings["sendEmailAddress"]; //发送方邮箱地址//简单邮件传输协议类System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient();client.Host = "smtp.163.com";//邮件服务器client.Port = 25;//smtp主机上的端口号,默认是25.client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;//邮件发送方式:通过网络发送到SMTP服务器client.Credentials = new System.Net.NetworkCredential(sendEmailUserName, sendEmaiPassword);//凭证,发件人登录邮箱的用户名和密码//电子邮件信息类System.Net.Mail.MailAddress fromAddress = new System.Net.Mail.MailAddress(sendEmailAddress);//发件人Email,在邮箱是这样显示的,[发件人:小明<panthervic@163.com>;]System.Net.Mail.MailAddress toAddress = new System.Net.Mail.MailAddress(receiveEmailAddress);//收件人Email,在邮箱是这样显示的, [收件人:小红<43327681@163.com>;]  System.Net.Mail.MailMessage mailMessage = new System.Net.Mail.MailMessage(fromAddress, toAddress);//创建一个电子邮件类mailMessage.Subject = subject;//string filePath = HttpContext.Current.Server.MapPath("/index.shtml");//邮件的内容可以是一个html文本.//System.IO.StreamReader read = new System.IO.StreamReader(filePath, System.Text.Encoding.UTF8);  //System.Text.Encoding.GetEncoding("GB2312")//string mailBody = read.ReadToEnd();//read.Close();mailMessage.Body = body;//可为html格式文本mailMessage.SubjectEncoding = System.Text.Encoding.UTF8;//邮件主题编码mailMessage.BodyEncoding = System.Text.Encoding.UTF8;//邮件内容编码mailMessage.IsBodyHtml = true;//邮件内容是否为html格式mailMessage.Priority = System.Net.Mail.MailPriority.Normal;//邮件的优先级,有三个值:高(在邮件主题前有一个红色感叹号,表示紧急),低(在邮件主题前有一个蓝色向下箭头,表示缓慢),正常(无显示).try{client.Send(mailMessage);//发送邮件//client.SendAsync(mailMessage, "ojb");异步方法发送邮件,不会阻塞线程.
            }catch (Exception e){throw new Exception(e.Message);}}}