1.IBLL

namespace IBll{    public interface IPersonBll    {        int Add(string name,string type);    }}

 

2.BLL 继承IBLL 并且实现

namespace BLL{    public class PersonBll : IPersonBll    {        private static readonly PersonBll instance = new PersonBll();        private PersonBll()        { }        public static PersonBll GetInstance()        {            return instance;        }        public int Add(string name, string type)        {            return 1;        }    }}

3.Factory 创建需要用的接口

namespace Factory{    public class Facotry    {        private static readonly Facotry instance = new Facotry();        private Facotry()        {        }        public static Facotry getInstance()        {            return instance;        }        public IPersonBll Create_IpersonBll()        {            return PersonBll.GetInstance();        }    }}

4.调用

IBll.IPersonBll personBll = Factory.Facotry.getInstance().Create_IpersonBll();