学步园

闲言不讲，直接上代码，如下三个文件，分属三个项目。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Remoting.Lifetime;
using System.Text;
using Contract;
namespace Application
{
    class Program
    {
        /// <summary>  
        /// 构建一个AppDomainSetup实例  
        /// 用于启用卷影复制并设置基本路径  
        /// </summary>  
        public static AppDomainSetup CreateAppDomainSetup()
        {
            AppDomainSetup setup = new AppDomainSetup();
            setup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory;
            setup.ShadowCopyFiles = "true";
            return setup;
        }

        /// <summary>  
        /// 从当前目录下的指定的程序集文件中加载指定的类型  
        /// </summary>  
        public static object CreateAndUnwrap(AppDomain appDomain, string assemblyFile, string typeName)
        {
            string fullName = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, assemblyFile);
            return appDomain.CreateInstanceFromAndUnwrap(fullName, typeName);
        }

        static void Main()
        {
            Console.WriteLine("Current AppDomain:{0}",
                AppDomain.CurrentDomain.FriendlyName);

            AppDomainSetup setup = CreateAppDomainSetup();

            //建立准备加载插件的AppDomain  
            AppDomain secAppDomain = AppDomain.CreateDomain("SecAppDomain", null, setup);

            //忽略新建立的AppDomain里面的调用租约管理  
            secAppDomain.DoCallBack(delegate
            {
                LifetimeServices.LeaseTime = TimeSpan.Zero;
            });

            IAddin addinOne = (IAddin)CreateAndUnwrap(
                                           secAppDomain, "Implement.dll", "Implement.AddinOne");

            Console.WriteLine(addinOne.Run("Test"));

            //卸载装入插件的AppDomain  
            AppDomain.Unload(secAppDomain);

            //由于插件所在的AppDmain已被卸载，所以以下的执行会出现异常  
            try
            {
                Console.WriteLine(addinOne.Run("Test"));
            }
            catch (Exception ex)
            {
                Console.WriteLine("发生调用异常：" + ex.Message);
            }

            Console.ReadLine();
        }
    }
}

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

namespace Contract
{

        public interface IAddin
        {
            string Run(string paramString);
        }

}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Contract;
namespace Implement
{
  
 
 
    public class AddinOne:MarshalByRefObject,IAddin  
    {  
        public string Run(string paramString)  
        {  
            const string resultString =  
                "Current AppDomain:{0},Param String:{1}!";  
 
            return string.Format(  
                resultString,  
                AppDomain.CurrentDomain.FriendlyName,  
                paramString);  
        }  
    }  
 

}