改天我在写详细注释吧，代码先贴出来，注释很明白了，应该无需多言。

  1 Controller代码：  2 public ActionResult ForgotPassword()  3         {  4             return View();  5         }  6         [ActionName("ForgotPassword"),HttpPost]  7         public ActionResult ForgotPasswordPost(ForgotPasswordModel model)  8         {  9             if (ModelState.IsValid) 10             { 11                 var user = _userDal.GetUserByName(model.Name); 12                 if (user == null) 13                 { 14                     ModelState.AddModelError("","用户名不存在！"); 15                     return View(); 16                 } 17                 if (string.IsNullOrWhiteSpace(user.Email)) 18                 { 19                     ModelState.AddModelError("", "该账户没有绑定邮箱，无法找回密码！"); 20                     return View(); 21                 } 22                 string res=_userDal.UserFindPassword(user.ID, user.Name, user.Email, HttpContext.Request.UserHostAddress); 23                 if (!string.IsNullOrEmpty(res)) 24                 { 25                     ModelState.AddModelError("", res); 26                     return View(); 27                 } 28                 else 29                 { 30                     ModelState.AddModelError("","邮件已发送，请注意查收！"); 31                     return View(); 32                 } 33             } 34             return View(model); 35         } 36  37 DAL层代码: 38   #region 密码找回 39         /// <summary> 40         /// 用户找回密码功能 41         /// </summary> 42         /// <param name="userId">用户ID</param> 43         /// <param name="userName">用户名</param> 44         /// <param name="ip">用户申请找回密码时候的IP</param> 45         /// <param name="email">用户的邮箱</param> 46         /// <returns></returns> 47         public string UserFindPassword(int userId, string userName, string email, string ip) 48         { 49             DateTime expirationTime = DateTime.Now.AddDays(1);//申请链接过期时间 50             Random random = new Random(); 51             var secretKey = random.Next(100000, 999999).ToString().ToPassword();//生成随机的Key 52             Web_UserFindPassword model = new Web_UserFindPassword 53             { 54                 UserID = userId, 55                 UserName = userName.Trim(), 56                 IP = ip, 57                 ExpirationTime = expirationTime, 58                 SecretKey = secretKey 59             }; 60             dbContext.Web_UserFindPassword.Add(model);//把申请信息存到数据库去 61             dbContext.SaveChanges(); 62             StringBuilder sb = new StringBuilder(); sb.Append("亲爱的" + userName + "您好：<br/><br/>"); 63             sb.Append("点击以下链接设置新密码。<br/><br/>"); 64             sb.Append("<a href =http://www.mamicode.com/"http://www.vimi8.com/Member/FindPassword?SecretKey=" + model.SecretKey + "&UserId=" + model.UserID + "&ExpirationTime=" + model.ExpirationTime + "\">http://www.vimi8.com/Member/FindPassword?SecretKey=" + model.SecretKey + "&UserId=" + model.UserID + "&ExpirationTime=" + "&ExpirationTime=" + model.ExpirationTime + " </a><br/><br/>"); 65             sb.Append("(如果无法点击该URL链接地址，请将它复制并粘帖到浏览器的地址输入框，然后单击回车即可。)<br/><br/>"); 66             sb.Append("注意:本链接有效期24小时，过期链接将会失效。在您点击一次后失效。<br/><br/>"); 67             sb.Append("我们将一如既往、热忱的为您服务！<br/><br/>"); 68             string messageBody = sb.ToString(); 69             string res = MailInfo.SendMail(email, "为米网找回密码", messageBody); 70             return res; 71         } 72  73         public Web_UserFindPassword GetFindPasswordModel(string secretKey, int userId, DateTime expirationTime) 74         { 75             return dbContext.Web_UserFindPassword.FirstOrDefault(x => x.ExpirationTime.Minute == expirationTime.Minute && x.SecretKey == secretKey && x.UserID == userId); 76         } 77  78         public void DeleteFindPasswordModel(int id) 79         { 80             var find = dbContext.Web_UserFindPassword.FirstOrDefault(x => x.ID == id); 81             if (find != null) 82             { 83                 dbContext.Web_UserFindPassword.Remove(find); 84                 dbContext.SaveChanges(); 85             } 86         } 87         #endregion 88  89 数据库设计： 90 using System; 91  92  93     public class Web_UserFindPassword 94     { 95         public int ID { get; set; } 96         public int? UserID { get; set; } 97         public string UserName { get; set; } 98         public DateTime ExpirationTime { get; set; } 99         public string SecretKey { get; set; }100         public string IP { get; set; }101     }