csharp: mappings using Dapper-Extensions+Dapper.net.

CREATE TABLE [PotoUsers]  
        (  
          [UserID] INT IDENTITY(1,1) PRIMARY KEY,  
          [UserName] NVARCHAR(50),  
          [FirstName] NVARCHAR(50),  
          [LastName] NVARCHAR(50),  
          [MiddleName] NVARCHAR(50),  
          [EmailID] NVARCHAR(50),
		  [Adddate] datetime  
        )  
GO  

 /// <summary>
    /// 20180212
    /// 涂聚文
    /// </summary>
    //[Table("PotoUsers")]
    public class PotoUsers
    {
        /// <summary>
        /// 
        /// </summary>
        //[Key]
        public int UserID { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string UserName { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string FirstName { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string LastName { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string MiddleName { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string EmailID { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public DateTime Adddate { get; set; }

    }

 /// <summary>
    /// 涂聚文
    /// 20180212
    /// </summary>
    public static class Mappings
    {      

        public static void Initialize()
        {
            DapperExtensions.DapperExtensions.DefaultMapper = typeof(PluralizedAutoClassMapper<>);

            DapperExtensions.DapperExtensions.SetMappingAssemblies(new[]
            {
                typeof(Mappings).Assembly
            });
        }
        /// <summary>
        /// 
        /// </summary>
        public class PotoUsersMapper : ClassMapper<PotoUsers>
        {
            /// <summary>
            /// 
            /// </summary>
            public PotoUsersMapper()
            {
                Table("PotoUsers"); //DuPotoUsers         
                Map(Ducel => Ducel.UserID).Column("UserID").Key(KeyType.Identity); //主键类型
                Map(Ducel => Ducel.UserName).Column("UserName");
                Map(Ducel => Ducel.FirstName).Column("FirstName");
                Map(Ducel => Ducel.LastName).Column("LastName");
                Map(Ducel => Ducel.MiddleName).Column("MiddleName");
                Map(Ducel => Ducel.EmailID).Column("EmailID");
                Map(Ducel => Ducel.Adddate).Column("Adddate");
                AutoMap();
            }
        }
    } 

       string  connStr = System.Configuration.ConfigurationManager.ConnectionStrings["conDuString"].ToString();
        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                try
                {
                    using (SqlConnection cn = new SqlConnection(connStr))
                    {

                            //1获取值
                            //cn.Open();
                            //int UserID = 1;
                            //PotoUsers potoUsers = cn.Get<PotoUsers>(UserID);
                            //cn.Close();
                            //Response.Write(person.UserName);

                         //2插入值
                        //cn.Open();
                        //PotoUsers potoUsers = new PotoUsers { UserName = "geovindu", MiddleName = "", EmailID = "geovindu@163.com", FirstName = "Foo", LastName = "Bar", Adddate = DateTime.Now };
                        //int id = cn.Insert(person);
                        //cn.Close();

                        //3 修改
                        //cn.Open();
                        //int UserID = 1;
                        //PotoUsers potoUsers = cn.Get<PotoUsers>(UserID);
                        //potoUsers.UserName = "涂聚文";
                        //potoUsers.LastName = "du";
                        //potoUsers.FirstName = "geovin";
                        //cn.Update(potoUsers);
                        //cn.Close();

                        //4.删除
                        //cn.Open();
                        //int UserID = 1;
                        //PotoUsers potoUsers = cn.Get<PotoUsers>(UserID);
                        //cn.Delete(potoUsers);
                        //cn.Close();

                        //5.
                        cn.Open();
                        var predicate = Predicates.Field<PotoUsers>(f => f.UserID, Operator.Like, true);
                        IEnumerable<PotoUsers> list = cn.GetList<PotoUsers>(predicate);
                        cn.Close();
                        Response.Write(list.ToList<PotoUsers>().Count.ToString());

                    }
                }
                catch (SqlException ex)
                {
                    Response.Write(ex.Message.ToString());
                }
            }


        }