using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace IBLL
{public  interface IHelloWord{string SayHello(string Name);}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using IBLL;namespace BLL
{public class HelloWord:IHelloWord{#region IHelloWord 成员public string SayHello(string Name){return  "Hello_"+Name;}#endregion}}

  <appSettings><add key="IBLL.IHelloWord" value="BLL,BLL.HelloWord"/></appSettings>

 说明：　　key值为接口的全称(命名空间+类名)，value值为实现接口的类，两部分组成，逗号前面为生成的dll名称，逗号后面为类名全称(命名空间+类名)。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
using System.Reflection;
using System.Configuration;namespace Common
{public class IOCReflecter{private static Hashtable s_type=null;static IOCReflecter(){s_type = new Hashtable();}public static T CreateIntance<T>(){Type t=typeof(T);//keyType type = s_type[t] as Type;//valueif (type == null){string[] AssemblyInfos = ConfigurationManager.AppSettings[t.FullName].Split(',');type = Assembly.Load(AssemblyInfos[0]).GetType(AssemblyInfos[1]);s_type.Add(t, type);}return (T)CreateObject(type) ;}/// <summary>/// 根据typeName获取Type对象/// </summary>/// <param name="typeName"></param>/// <returns></returns>public static Type GetType(string typeName){if (string.IsNullOrWhiteSpace(typeName)){return null;}return Type.GetType(typeName);}/// <summary>/// 获取对象/// </summary>/// <param name="t"></param>/// <returns></returns>private static object CreateObject(Type t){if (t == null){return null;}//查找没有参数的构造函数//如果需要初始化带参数的构造函数 t.GetConstructors() 获取所有的构造函数 ，it.GetParameters()获取构造函数所有的参数，ConstructorInfo NonParameterConstructors= t.GetConstructors().Where(it=>it.GetParameters().Length==0).FirstOrDefault();if (NonParameterConstructors == null){throw new Exception( t.FullName+"必须有一个无参数或默认的构造函数");}//调用数构造函数创建对象return t.InvokeMember(null, BindingFlags.CreateInstance, null, null, null);}}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using IBLL;
using Common;namespace IOCTest.Controllers
{public class HomeController : Controller{//// GET: /Home/public ActionResult Index(){//获取实例化对象IHelloWord hello = IOCReflecter.CreateIntance<IHelloWord>();ViewBag.Message = hello.SayHello("eric");return View();}}
}

@{ViewBag.Title = "Index";
}<h2>@ViewBag.Message </h2>