七层架构

以你之姓@ 2021-06-24 15:58 415阅读 0赞

# 简述 #

师傅给讲过反射\+配置文件之后豁然开朗，对七层整体的架构了解又有了一个新的认识，今天开始机房七层登陆的，，嗯，算是重构吧，在之前的七层的基础上重新做一个新的认识。

**实体层**（Model）完成了，很简单，只有UserID和UserPwd

**接口层**（IDAL）其次，简单的写出一个方法，在DAL层里面使用

**DAL层**，这个真的是了解了太多了，包括从开始的命名，反射就用在这里，为什么能换数据库，就是全都在命名上。

sqlhelper主要作用就是用来连接数据库进行一系列的操作

sqlchargeDAL和sqltestDAL两个分别是对不同数据库的调用

**UI层**，主要是将需要用到的东西实例化，添加配置文件，在这里配置文件要细说一下，这些东西敲好之后都会封装成为dll文件，要想换数据库的话，就是反射\+抽象工厂\+配置文件，还数据库的话就重新写一个配置文件，然后将配置文件换掉就好了，快捷方便。

**外观层**（Facade）就是将UI和DAL层的数据进行一个交互，就相当于一个中介的作用。目的是解耦，让UI和BLL层少一些耦合，UI的代码更加的清晰。

**工厂层**（Factory），这就是抽象工厂层，用上反射，搭配着配置文件来选择不同的DB。

**逻辑层**（BLL），首先将外观层传进来的数据进行一个逻辑操作，然后交给DAL层操作，其次就是从DAL层传回来时还需要进行逻辑操作返回需要用到的值。

# 七层代码 #

## 实体层 ##

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    
    namespace Model
    {
        public class UserInfo
        {
            private string userid;
            private string userPwd;
            private string level;
            private string name;
            private string head;
            public string UserID
            {
                get { return userid; }
                set { userid = value; }
            }
            public string UserPwd
            {
                get { return userPwd; }
                set { userPwd = value; }
            }
            public string UserLevel
            {
                get { return level; }
                set { level = value; }
            }
            public string UserName
            {
                get { return name; }
                set { name = value; }
            }
            public string Head
            {
                get { return head; }
                set { head = value; }
            }
        }
    }

##     ##

## UI层 ##

using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    
    
    namespace LoginUI
    {
        public partial class Form1 : Form
        {
            public static string level;
            public Form1()
            {
                InitializeComponent();
            }
            public void btnLogin_Click(object sender, EventArgs e)
            {
                //实例化用户
                Model.UserInfo user = new Model.UserInfo();
                user.UserID = txtUserID.Text.ToString();
                user.UserPwd = txtUserPwd.Text;
    
    
                //传入外观层
                LoginFacade.LoginFacade facade = new LoginFacade.LoginFacade();
                IList<Model.UserInfo> serveruser = facade.SelectUser(user);
    
    
                if (user.UserPwd != serveruser[0].UserPwd.ToString().Trim())
                {
                    MessageBox.Show("登陆失败");
                }
                else
                {
                    string level = serveruser[0].UserLevel.ToString().Trim();
                    MessageBox.Show(level + " 登陆成功");
                    this.Hide();
                    //调用frmMain，把值传到frmMain中
                    frmMain.frmMain fm = new frmMain.frmMain(level, user.UserID.ToString());
                    fm.Show();
                }
            }
        }
    }

##     ##

## Facade层 ##

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    
    namespace LoginFacade
    {
        public class LoginFacade
        {
            public IList<Model.UserInfo> SelectUser(Model.UserInfo userInfo)
            {
                LoginBLL.LoginBLL userBLL = new LoginBLL.LoginBLL();
                IList<Model.UserInfo> user = userBLL.UserBLL(userInfo);
                return user;
            }
        }
    }

##     ##

## IDAL层 ##

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Data.SqlClient;
    using System.Data;
    
    namespace LoginIDAL
    {
        public interface IDAL
        {
            IList<Model.UserInfo> selectUser(Model.UserInfo userInfo);
        }
    }

##     ##

## DAL层 ##

### sqlhelper ###

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Data.SqlClient;
    using System.Data;
    using System.Configuration;
    using System.Windows.Forms;
    
    namespace LoginDAL
    {
        public class SqlHelper
        {
            private SqlConnection conn = null;
            private SqlCommand cmd = null;
            private SqlDataReader sdr = null;
    
            public SqlHelper()
            {
                string connStr = ConfigurationManager.AppSettings["ConnStr"];
                conn = new SqlConnection(connStr);
            }
            private SqlConnection GetConn()
            {
                if (conn.State == ConnectionState.Closed)
                    conn.Open();
                return conn;
            }
            /// <summary>
            /// 执行并且返回值为受影响行数的执行不带参数的sql语句或存储过程
            /// </summary>
            /// <param name="cmdText">sql语句</param>
            /// <param name="ct">命令类型</param>
            /// <returns>返回受影响行数</returns>
            public int ExecuteNonQuery(string cmdText, CommandType ct)
            {
                int res;
                try
                {
                    cmd = new SqlCommand(cmdText, GetConn());
                    cmd.CommandType = ct;
                    res = cmd.ExecuteNonQuery();
                }
                catch (Exception ex)
                {
                    throw ex;
                }
                finally
                {
                    if (conn.State == ConnectionState.Open)
                        conn.Close();
                }
                return res;
            }
            /// <summary>
            /// 执行并且返回值为受影响行数的执行带参数的sql语句或存储过程
            /// </summary>
            /// <param name="cmdText">sql语句</param>
            /// <param name="paras">需要查询的参数</param>
            /// <param name="ct">命令类型</param>
            /// <returns>返回受影响的行数</returns>
            public int ExecuteNonQuery(string cmdText, SqlParameter[] paras, CommandType ct)
            {
                int res;
                using (cmd = new SqlCommand(cmdText, GetConn()))
                {
                    cmd.CommandType = ct;
                    cmd.Parameters.AddRange(paras);
                    res = cmd.ExecuteNonQuery();
                    conn.Close();
                }
                return res;
            }
            /// <summary>
            /// 执行并且返回值为Datatable的执行带参数的查询sql语句或存储过程
            /// </summary>
            /// <param name="cmdText">sql语句</param>
            /// <param name="ct">命令类型</param>
            /// <returns>返回Datatable</returns>
            public DataTable ExecuteQuery(string cmdText, CommandType ct)
            {
                DataTable dt = new DataTable();
                cmd = new SqlCommand(cmdText, GetConn());
                cmd.CommandType = ct;
                using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
                {
                    dt.Load(sdr);
                }
                return dt;
            }
            /// <summary>
            /// 执行并且返回值为Datatable的执行带参数的查询sql语句或存储过程
            /// </summary>
            /// <param name="cmdText">查询SQL语句或存储过程</param>
            /// <param name="paras">参数集合</param>
            /// <param name="ct">命令类型</param>
            /// <returns>返回Datatable</returns>
            public DataTable ExecuteQuery(string cmdText, SqlParameter[] paras, CommandType ct)
            {
                DataTable dt = new DataTable();
                cmd = new SqlCommand(cmdText, GetConn());
    
                cmd.Parameters.AddRange(paras);
                using (sdr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
                {
                    dt.Load(sdr);
                }
                return dt;
            }
        }
    }

###     ###

### sqlnewchargeDAL ###

using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Linq;
    using System.Text;
    using Model;
    using System.Data.SqlClient;
    
    namespace LoginDAL
    {
        class SqlnewchargeDAL : LoginIDAL.IDAL
        {
            //public DataTable selectUser(UserInfo userInfo)
            public IList<Model.UserInfo> selectUser(UserInfo userInfo)
            {
                SqlHelper sqlhelper = new SqlHelper();
                //SqlParameter[] sqlparams = { new SqlParameter("@userID", userInfo.UserID), new SqlParameter("@userPwd", userInfo.UserPwd) };
                SqlParameter[] sqlparams = { new SqlParameter("@userID", userInfo.UserID)};
                //string sql = @"SELECT * FROM [User_Info] WHERE UserID=@UserID and UserPwd=@UserPwd";
                string sql = @"SELECT * FROM [User_Info] WHERE UserID=@UserID";
                DataTable table = sqlhelper.ExecuteQuery(sql, sqlparams, CommandType.Text);
                IList<Model.UserInfo> user = LoginDAL.ConvertHelper<Model.UserInfo>.ConvertToModel(table);
                return user;
            }
        }
    }

##     ##

## Factory ##

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Reflection;
    using System.Configuration;
    
    namespace LoginFactory
    {
        public class ServerFactory
        {
            string AssemblyName = "LoginDAL";
            string strDB = ConfigurationManager.AppSettings["DB"];
            public LoginIDAL.IDAL CreateUser()
            {
                string ClassName = AssemblyName + "." +strDB+ "DAL";
                return (LoginIDAL.IDAL)Assembly.Load(AssemblyName).CreateInstance(ClassName);
            }
        }
    }

##     ##

## BLL层 ##

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Data;
    
    namespace LoginBLL
    {
        public class LoginBLL
        {
            public IList<Model.UserInfo> UserBLL(Model.UserInfo userInfo)
            {
                LoginFactory.ServerFactory fact = new LoginFactory.ServerFactory();
                LoginIDAL.IDAL idal = fact.CreateUser();
    
                IList<Model.UserInfo> user = idal.selectUser(userInfo);
                //返回值为用户级别
                //string flag = null;
                //判断是有有此用户
                if (user.Count == 0)
                {
                    user = null;
                }
                else
                {
                    //flag = (user[0].UserPwd.Trim() == userInfo.UserPwd) ? "success" : "fail";
                }
                return user;
            }
        }
    }