三层架构之工厂模式（基于泛型）

1、目录

2、model层

    2.1、BaseModel 

namespace Study.Model
{
    public abstract class BaseModel:IEquatable<BaseModel>
    {
        public bool Equals(BaseModel other)
        {
            throw new NotImplementedException();
        }
    }
}

　 2.2、User

namespace Study.Model
{
    public class User:Model.BaseModel
    {
        private string userName;
        private int age;
        public string UserName
        {
            get { return userName; }
            set { userName = value; }
        }      

        public int Age
        {
            get { return age; }
            set { age = value; }
        }
    }
}

3、IDAL层

   3.1、IBaseDAL

namespace Study.IDAL
{
    public interface IBaseDAL<T> where T:Study.Model.BaseModel///T必须是BaseModel的派生类
    {
       int add(T model);
       int delete(T model);
       int insert(T model);
       int update(T model);
       List<T> getList(T model);
    }
}

　　3.2、IUserDAL

namespace Study.IDAL
{
   public interface IUserDAL:IBaseDAL<User>
    {
    }
}

　　

4、BLL层

   4.1、BaseBLL

namespace Study.BLL
{
    public class BaseBLL<M> where M:Study.Model.BaseModel
    {

        private Study.IDAL.IBaseDAL<M> dal;
        private string DALClassName;
        public BaseBLL(string className) {
            DALClassName = className;
            dal = (Study.IDAL.IBaseDAL<M>)Study.FactoryDAL.DataAccess<M>.CreateDAL(DALClassName);
        }

        public int add(M model) {
            dal.add(model);
            return 0;
        }
        int delete(M model) {
            return 0;
        }
        int insert(M model)
        {
            return 0;
        }
        int update(M model)
        {
            return 0;
        }
        List<M> getList(M model)
        {
            List<M> a=new List<M>();
            return a;
        }

    }
}

　4.2、UserBLL

namespace Study.BLL
{
    public class UserBLL:Study.BLL.BaseBLL<Study.Model.User>
    {
        public UserBLL():base("UserDAL") { 
           
        }
    }
}

5、FactoryDAL

namespace Study.FactoryDAL
{
    public class DataAccess<T> where T:Study.Model.BaseModel
    {        
        public static readonly string path="Study.SQLServerDAL";
        public static Study.IDAL.IBaseDAL<T> CreateDAL(string dalClassName)
        {
            string type = typeof(T).ToString();
            System.Reflection.Assembly a= System.Reflection.Assembly.Load(path);
            return (Study.IDAL.IBaseDAL<T>)System.Reflection.Assembly.Load(path).CreateInstance(path+"."+dalClassName);
        }
    }
}

　6、Vie层

        private void button1_Click(object sender, EventArgs e)
        {
            User user = new User();
            Study.BLL.BaseBLL<User> baseUserBll = new Study.BLL.BaseBLL<User>("UserDAL");
            Study.BLL.UserBLL userBLL = new BLL.UserBLL();
            int a = baseUserBll.add(user);
            int b = userBLL.add(user);
        }

　　在veiw层里调用BLL层用反射机制动态反回DAL类时会出现程序集Study.SQLServerDAL找不到的错误，解决办法：在VIEW层里将Study.SQLServerDAL引用加上去。虽然view层不直接访问DAL层而是由BLL层来访问。