三层架构之泛型抽象

关于泛型抽象工厂，最近自己写了一个项目，现在拿出来和大家分享，有助于我们学习。

项目截图如下：

XU.Model层中有一个抽象类BaseModel.cs是用户实体类，继承与BaseModel类，是用于类型安全考虑的,从而让 各实体类有一个统一的父类，在其他层使用的时候，可以使用里氏替换原则的考虑。

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

namespace XU.Model
{
    /// <summary>
    /// 该抽象类为所有实体类的父类
    /// 所有实体类继承该抽象类，为保持类型一致而设计的父类，也是出于安全性的考虑
    /// </summary>
    public abstract class BaseModel
    {

    }
}

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace XU.Model.Student
 8 {
 9     /// <summary>
10     /// 实体类Student继承自BaseModel
11     /// 调用时就可以通过BaseModel model=new Student();
12     /// </summary>
13     public class Student : BaseModel
14     {
15         public int Id { get; set; }
16         public string Name { get; set; }
17         public string SubjectName { get; set; }
18         public int Score { get; set; }
19     }
20 }

XU.FactoryDAL层是用于反射获取实例，其中只用一个类。

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

namespace XU.FactoryDAL
{
    public class DataAccess<T> where T : class
    {
        //获取配置路径
        private static readonly string path = System.Configuration.ConfigurationManager.AppSettings["DAL"];
        private DataAccess() { }
        /// <summary>
        /// 创建实例  反射创建实例
        /// </summary>
        /// <param name="Type"></param>
        /// <returns></returns>
        public static T CreateDAL(string Type)
        {
            string className = string.Format(path + ".{0}", Type);
            try
            {
                return (T)System.Reflection.Assembly.Load(path).CreateInstance(className);
            }
            catch (Exception ex)
            {

                throw new Exception(ex.Message.ToString());
            }
        }
    }
}

XU.IDAL层依赖与XU.Model，其中包含一个基类接口IBaseDal.cs,还有一个用于定义一些基类接口没有方法的接口IStudentDal.cs,继承接口IBaseDal<T>。

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

namespace XU.IDAL
{
    /// <summary>
    /// 所有的dal基本都有增删改查等功能，提取到dal接口层
    /// 所有实现该接口的类必须实现所有的未实现的成员
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public interface IBaseDal<T> where T:XU.Model.BaseModel,new()
    {
        int Add(T model);
        int Delete(int Id);
        int Update(T model);
        T GetModel(int Id);
    }
}

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

namespace XU.IDAL
{
    /// <summary>
    /// 需有特殊的方法的  可定义子接口
    /// 如：登录   判断用户名是否存在
    /// </summary>
    public interface IStudentDal:IBaseDal<Model.Student.Student>
    {

        /// <summary>
        /// 判断用户名是否存在
        /// </summary>
        /// <param name="userName"></param>
        /// <returns></returns>
        // bool Exists(string userName);
        /// <summary>
        /// 登录
        /// </summary>
        /// <param name="name"></param>
        /// <param name="pwd"></param>
        /// <returns></returns>
        // Model.UserModel Login(string name, string pwd);

        //显示方法可写到IBaseDal.cs 不属于特殊方法
        List<Model.Student.Student> GetList(); 
        
    }
}

实现XU.IDAL中接口有2个类库，一个是MSSQL类库，一个是MYSQL类库，这2两个类库都依赖于XU.Model和XU.IDAL,下面是实现方法。

XU.MSSQLDAL的实现方法如下：

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using XU.Model.Student;

namespace XU.MSSQDAL
{
    public class StudentDal : IDAL.IStudentDal
    {
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public int Add(Student model)
        {
            string sql = string.Format("insert into Student values('{0}','{1}',{2})", model.Name, model.SubjectName, model.Score);
            return DBHelper.ExecuteNonQuery(sql);
        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public int Delete(int Id)
        {
            string sql = "Delete Student where Id=" + Id;
            return DBHelper.ExecuteNonQuery(sql);
        }
        /// <summary>
        /// 查询显示
        /// </summary>
        /// <returns></returns>
        public List<Student> GetList()
        {
            string sql = "select * from Student";
            return DBHelper.GetList<Student>(sql);
        }
        /// <summary>
        /// 反填
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public Student  GetModel(int Id)
        {
            string sql = "select * from Student where Id=" + Id;
            return DBHelper.GetList<Student>(sql).FirstOrDefault();
        }
        /// <summary>
        /// 修改
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public int Update(Student model)
        {
            string sql = string.Format("Update Student Set Name='{0}',SubjectName='{1}',Score={2} where Id={3}",model.Name,model.SubjectName,model.Score,model.Id);
            return DBHelper.ExecuteNonQuery(sql);
        }
    }
}

XU.MYSQLDAL的实现方法如下：

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using XU.Model.Student;

namespace XU.MYSQLDAL
{
    public class StudentDal : IDAL.IStudentDal
    {
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public int Add(Student model)
        {
            string sql = string.Format("insert into Student(Name,SubjectName,Score) values('{0}','{1}',{2})", model.Name, model.SubjectName, model.Score);
            return MySqlDBHelper.ExecuteNonQuery(sql);
        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public int Delete(int Id)
        {
            string sql = "Delete from Student where Id=" + Id;
            return MySqlDBHelper.ExecuteNonQuery(sql);
        }
        /// <summary>
        /// 查询显示
        /// </summary>
        /// <returns></returns>
        public List<Student>  GetList()
        {
            string sql = "select * from Student";
            return MySqlDBHelper.GetList<Student>(sql);
        }
        /// <summary>
        /// 反填
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public Student GetModel(int Id)
        {
            string sql = "select * from Student where Id=" + Id;
            return MySqlDBHelper.GetList<Student>(sql).FirstOrDefault();
        }

        public int Update(Student model)
        {
            string sql = string.Format("update Student set Name='{0}',SubjectName='{1}',Score='{2}'  where  Id ={3}", model.Name, model.SubjectName, model.Score, model.Id);
            return MySqlDBHelper.ExecuteNonQuery(sql);
        }

       

    }
}

XU.BLL业务逻辑层中包含了一个用于继承的基类BaseBLL<T>和用户业务逻辑StudentBll类，这层依赖XU.IDAL,XU.Model,XU.FactoryDAL库

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

namespace XU.BLL
{
    public class BaseBLL<T> where T:XU.Model.BaseModel,new()
    {
        protected XU.IDAL.IBaseDal<T> Dal;
        public BaseBLL(string type)
        {
            //通过工厂得到dal
            Dal = XU.FactoryDAL.DataAccess<XU.IDAL.IBaseDal<T>>.CreateDAL(type);
        }
        /// <summary>
        /// 增加
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public virtual int Add(T model)
        {
            return Dal.Add(model);
        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public virtual int Delete(int Id)
        {
            return Dal.Delete(Id);
        }
        /// <summary>
        /// 修改
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public virtual int Update(T model)
        {
            return Dal.Update(model);
        }
        /// <summary>
        /// 反填
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        public virtual T GetModel(int Id)
        {
            return Dal.GetModel(Id);
        }
    }
}

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using XU.Model.Student;

namespace XU.BLL
{
    public class StudentBll:BaseBLL<XU.Model.Student.Student>
    {
        private const string _Type = "StudentDal";
        private XU.IDAL.IStudentDal _Dal;
        public StudentBll() : base(_Type)
        {
            _Dal = base.Dal as XU.IDAL.IStudentDal;
            if(_Dal == null)
            {
                throw new NullReferenceException(_Type);
            }
        }
        /// <summary>
        /// 查询方法
        /// </summary>
        /// <returns></returns>
        public List<Student> GetList()
        {
            return _Dal.GetList();
        }
    }
}

XU.ConsoleDemo是一个MVC项目，用这个讲解抽象工厂更简单和直观，项目中只包含了基础的增删改查操作

控制器如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using XU.BLL;
using XU.Model.Student;
using Newtonsoft.Json;
using System.Data;

namespace XU.ConsoleDemo.Controllers
{
    public class SchoolController : Controller
    {
        StudentBll bll = new StudentBll();
        /// <summary>
        /// 添加显示方法
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public ActionResult Create()
        {
            return View();
        }
        /// <summary>
        /// 添加执行方法
        /// </summary>
        /// <param name="stu"></param>
        /// <returns></returns>
        [HttpPost]
        public ActionResult Create(Student stu)
        {
            int n = bll.Add(stu);
            if (n > 0)
            {
                return Content("添加成功");
            }
            else
            {
                return Content("添加失败");
            }
        }
        /// <summary>
        /// 学生显示
        /// </summary>
        /// <returns></returns>
        public ActionResult Index()
        {
            var list =  bll.GetList();
            var json = JsonConvert.SerializeObject(list);
            List<Student> show = JsonConvert.DeserializeObject<List<Student>>(json);
            return View(show);
        }
        public ActionResult Delete(int Id)
        {
            int n = bll.Delete(Id);
            if (n > 0)
            {
                return Content("删除成功");
            }
            else
            {
                return Content("删除失败");
            }
        }
        /// <summary>
        /// 修改反填
        /// </summary>
        /// <param name="Id"></param>
        /// <returns></returns>
        [HttpGet]
        public ActionResult Edit(int Id)
        {
           Student stu =  bll.GetModel(Id);
          
            return View(stu);
        }
        /// <summary>
        /// 修改执行方法
        /// </summary>
        /// <param name="stu"></param>
        /// <returns></returns>
        [HttpPost]
        public ActionResult Edit(Student stu)
        {
            int n = bll.Update(stu);
            if (n > 0)
            {
                return Content("修改成功");
            }
            else
            {
                return Content("修改失败");
            }
        }

    }
}

web.config程序集名称

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <!--DAL路径-->
    <add key="DAL" value="XU.MYSQLDAL"/>
      <!--
        <add key="DAL" value="XU.MSSQDAL"/>
        -->
  </appSettings>
</configuration>

注意：XU.ConsoleDemo是不会直接引用XU.MSSQLDAL和XU.MYSQLDAL的，但是XU.ConsoleDemo中的Debug目录下要把编译好的XU.MSSQLDAL.dll和XU.MYSQLDAL.dll放进去，如果是网站就要放入网站中的Bin文件夹下

 源码下载: https://pan.baidu.com/s/1CsbkCQl2M8IQ7BEtVMLKng 提取码: 5w36