最简单的三层实例【插入据

三层常用就是UI,DAL,MODEL 还有其他的比如接口 模式等 这里以普通三层为例 实现插入数据的功能 。

先定义model实体类

  private int uid;
       private string uname;
       private string upass;
       public int UserId
       {
           get { return uid; }
           set { uid = value; }
       }
       public string UserName
       {
           get { return uname; }
           set { uname = value; }
       }
       public string UserPass
       {
           get { return upass; }
           set { upass = value; }
       }

DAL数据访问层；

  public UserService()
        {
        }
        private string db = System.Configuration.ConfigurationSettings.AppSettings["ConstrSQL"].ToString();//数据库连接字符串
        /// <summary>
        /// 执行数据插入
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public bool Insert(Model.UserInfo model)
        {
            using (SqlConnection conn = new SqlConnection())
            {
                conn.ConnectionString = db;
                conn.Open();
                string strsql = "insert into UserInfos(UserName,UserPass)values(@uname,@upass)";
                SqlCommand cmd = new SqlCommand(strsql, conn);
                cmd.Parameters.Add("@uname", SqlDbType.VarChar, 50);
                cmd.Parameters.Add("@upass", SqlDbType.VarChar, 50);
                cmd.Parameters["@uname"].Value = model.UserName;
                cmd.Parameters["@upass"].Value = model.UserPass;
                if (cmd.ExecuteNonQuery() > 0)
                {
                    return true;
                }
                else
                {
                    return false;
                }
                conn.Dispose();
                conn.Close();
            }
        }

 BLL层我的理解就是UI与DAL之间的桥梁 ，主要是一调用的函数（方法）

  public bool BLL_Insert(Model.UserInfo mu)
       {
           DAL.UserService du = new DAL.UserService();
           return du.Insert(mu);
       }

 UI层调用BLL

Model.UserInfo mu = new Model.UserInfo();
        mu.UserName = TextBox1.Text;
        mu.UserPass = TextBox2.Text;
        DAL.UserService du = new DAL.UserService();
        du.Insert(mu);
        Response.Write("提交成功！");
        TextBox2.Text = "";

三层顺序model -dal-bll，BLL引用DAL，DAL引用MODEL