创建一个借口类IDAL：不需要方法体的方法。将class装换成interface

MVC:web.config <add key="CDAL" value="DAL"/>

API的web.config <add key="CDAL" value="DAL"/>添加到<appSettings>

创建一个接口  没有方法体的方法

namespace IDAL

{

using MODEL;

public interface IdalUser

{

int UsertAdd(Usert user);

int Login(string name,string pass);

}

}

namespace IDAL

{

using MODEL;

public interface IImagedal

{

int ImagesAdd(ImageModel img);

/// <summary>

/// 获取所有的信息

/// </summary>

/// <returns></returns>

List<ImageModel> GetImage();

}

}

建立一个工厂类：

namespace GongChang

{

using System.Configuration;

using System.Reflection;

using IDAL;

public class gongchang

{

private static readonly string kname = ConfigurationManager.AppSettings["CDAL"];

public IdalUser CreateuserDAL()

{

return (IdalUser)Assembly.Load(kname).CreateInstance(kname + ".UsertDal");

}

public IImagedal CreateimgDAL()

{

return (IImagedal)Assembly.Load(kname).CreateInstance(kname + ".ImageDal");

}

}

}

BLL实例化：

using MODEL;

using DAL;

using GongChang;

using IDAL;

gongchang gc = new gongchang();

IImagedal bll = null;

public ImagesBll()

{

if (bll == null)

{

bll = gc.CreateimgDAL();

}

}

//ImageDal bll = new ImageDal();

MVC api 记者引用接口