基本三层架构的一些代码

 ***********特别注意用户信息存在session中在其他页面的取值方法

       ThreeTies.Model.User  u= Session["User"]  as ThreeTies.Model.User;

        labUserName=u.UserName;

        labUserPwd=u.UserPwd;

1.通用类层的代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace ThreeTies.DBUtility
{
    /// <summary>
    /// 封装常见的数据库访问方法
    /// </summary>
    public class DBHelp
    {
        //连接串
        private static string _connStr="server=.;uid=sa;pwd=;database=ThreeTies";
        //连接对象
        private static SqlConnection sqlcon = null;

        /// <summary>
        /// 建立数据库连接
        /// </summary>
        private static void CreateConnection()
        {
            if (sqlcon == null)
            {
                sqlcon = new SqlConnection(_connStr);
                sqlcon.Open();
            }
            else if (sqlcon.State == ConnectionState.Closed || sqlcon.State == ConnectionState.Broken)
            {
                sqlcon.Close();
                sqlcon.Open();
            }
        }
        /// <summary>
        /// 根据查询语句，执行单向的Insert、Update、Delete
        /// </summary>
        /// <param name="strsql">查询语句</param>
        /// <returns>受影响的行数</returns>
        public static int ExecuteNoQuery(string strsql)
        {
            int i=-1;

            try
            {
                CreateConnection();
                SqlCommand sqlcmd = new SqlCommand(strsql, sqlcon);
                i = sqlcmd.ExecuteNonQuery();
                return i;
            }
            catch (Exception ex)
            {               
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 根据查询语句，执行单向的Insert、Update、Delete
        /// </summary>
        /// <param name="strsql">查询语句</param>
        /// <param name="param">语句中的参数数组</param>
        /// <returns>受影响的行数</returns>
        public static int ExecuteNoQuery(string strsql, params SqlParameter[] param)
        {
            int i = -1;

            try
            {
                CreateConnection();
                SqlCommand sqlcmd = new SqlCommand(strsql, sqlcon);
                sqlcmd.Parameters.AddRange(param);
                i = sqlcmd.ExecuteNonQuery();
                return i;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 根据查询数据，执行双向的查询
        /// </summary>
        /// <param name="strsql">查询语句</param>
        /// <returns>查询的结果-表集合</returns>
        public static DataTable GetTable(string strsql)
        {
            try
            {
                CreateConnection();
                SqlDataAdapter sda = new SqlDataAdapter(strsql, sqlcon);
                DataSet ds = new DataSet();
                sda.Fill(ds, "temp");
                sqlcon.Close();
                return ds.Tables["temp"];
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 根据查询数据，执行双向的查询
        /// </summary>
        /// <param name="strsql">查询语句</param>
        /// <param name="param">查询参数</param>
        /// <returns>查询的结果-表集合</returns>
        public static DataTable GetTable(string strsql, params SqlParameter[] param)
        {
            try
            {
                CreateConnection();
                SqlDataAdapter sda = new SqlDataAdapter(strsql, sqlcon);
                sda.SelectCommand.Parameters.AddRange(param);
                DataSet ds = new DataSet();
                sda.Fill(ds, "temp");
                sqlcon.Close();
                return ds.Tables["temp"];
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 根据查询要求返回轻量级对象DataReader
        /// </summary>
        /// <param name="strsql">查询语句</param>
        /// <returns>返回的对象</returns>
        public static SqlDataReader GetReader(string strsql)
        {
            try
            {
                CreateConnection();
                SqlCommand sqlcmd = new SqlCommand(strsql, sqlcon);
                SqlDataReader sdr = sqlcmd.ExecuteReader(CommandBehavior.CloseConnection);
                return sdr;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 根据查询要求返回轻量级对象DataReader
        /// </summary>
        /// <param name="strsql">查询语句</param>
        /// <param name="param">查询参数</param>
        /// <returns>返回的对象</returns>
        public static SqlDataReader GetReader(string strsql, params SqlParameter[] param)
        {
            try
            {
                CreateConnection();
                SqlCommand sqlcmd = new SqlCommand(strsql, sqlcon);
                sqlcmd.Parameters.AddRange(param);
                SqlDataReader sdr = sqlcmd.ExecuteReader(CommandBehavior.CloseConnection);
                return sdr;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }
    }
}

2.数据防问层的代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using ThreeTies.DBUtility;
using ThreeTies.Model;
using System.Data.SqlClient;

namespace ThreeTies.SqlServerDAL
{
    /// <summary>
    /// 角色的数据访问层
    /// </summary>
    public  class RoleService
    {
        //该查询的特点：因为用了DataReader,所以在查询期间是不会释放连接的
        public static Role GetRole(int roleID)
        {
            Role role = null;
            //给查询语句定义的参数
            SqlParameter[] param=new  SqlParameter[]{
                new SqlParameter("@RoleID",roleID)
            };
            //using语句能自动释放对象
            using (SqlDataReader sdr = DBHelp.GetReader("select * from [Role] where RoleID=@RoleID", param))
            {
                if (sdr.Read())
                {
                    role = new Role();
                    //role.RoleID = roleID;
                    role.RoleID = (int)sdr.GetValue(0);
                    role.RoleName = (string)sdr.GetValue(1);
                }
                sdr.Close();
            }
            return role;
        }
    }
}

using ThreeTies.Model;
using ThreeTies.DBUtility;
using System.Data.SqlClient;
using System.Data;

namespace ThreeTies.SqlServerDAL
{
    //用户的基础服务类
    public class UserService
    {
        //添加用户
        public static int AddUser(User u)
        {
            try
            {
                SqlParameter[] param = new SqlParameter[]{
                    new SqlParameter("@UserName",u.UserName),
                    new SqlParameter("@UserPassword",u.UserPassword),
                    new SqlParameter("@RoleID",u.Role.RoleID)
                };
                int i = DBHelp.ExecuteNoQuery("insert into [User] values(@userName,@UserPassword,@RoleID)", param);
                return i;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        //根据用户的账号返回用户的信息
        public static User GetUserByUserID(string userName)
        {      
            User u=null;
            try
            {
                SqlParameter[] param = new SqlParameter[]{
                    new SqlParameter("@UserName",userName)
                };

                DataTable dt = DBHelp.GetTable("select * from [User] where UserName=@UserName", param);
                //如果用户存在
                if (dt.Rows.Count > 0)
                {
                    u = new User();
                    u.UserName = dt.Rows[0]["UserName"].ToString();
                    u.UserPassword = dt.Rows[0]["UserPassword"].ToString();
                    u.Role = new Role();
                    u.Role = RoleService.GetRole(int.Parse(dt.Rows[0]["RoleID"].ToString()));
                }
                return u;
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }
    }
}

3.业务逻辑层的代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using ThreeTies.Model;
using ThreeTies.SqlServerDAL;

namespace ThreeTies.BLL
{
    //用户管理类
    public class UserManager
    {
        /// <summary>
        /// 注册方法
        /// </summary>
        /// <param name="u">注册的用户信息</param>
        /// <returns>注册是否成功</returns>
        public static bool Register(string userName,string userPassword,int roleID)
        {
            int i = -1;
            //封装用户信息
            User u = new User();
            u.UserName = userName;
            u.UserPassword = StringMD5.GetMD5(userPassword);//加密处理
            u.Role = RoleService.GetRole(roleID);

            try
            {
                i = UserService.AddUser(u);
                if (i > 0)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        /// <summary>
        /// 提供登陆的账号、密码实现验证,并返回该对象
        /// </summary>
        /// <param name="userName">账号</param>
        /// <param name="userPassword">密码</param>
        /// <param name="u">返回的用户信息</param>
        /// <returns>登陆是否成功</returns>
        public static bool Login(string userName,string userPassword,out User u)
        {
            User currentUser = UserService.GetUserByUserID(userName);

            if (currentUser == null)
            {
                u = null;
                return false;
            }
            else if (currentUser.UserPassword == StringMD5.GetMD5(userPassword))
            {
                u = currentUser;//当前用户信息返回
                return true;
            }
            else
            {
                u = null;
                return false;
            }           
        }
    }
}