C# 通过 AppDomain 应用程序域实现程序集动态卸载或加载

using Kernel.ServiceAgent;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.Remoting;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Kernel.App
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("");

            using (ServiceManager<IObjcet> manager = new ServiceManager<IObjcet>()) 
            {
                string result = manager.Proxy.Put("apprun one");
                Console.WriteLine(result);
                Console.WriteLine("");
                Console.WriteLine("                         Thread AppDomain info                             ");
                Console.WriteLine(manager.CotrProxy.FriendlyName);
                Console.WriteLine(Thread.GetDomain().FriendlyName);
                Console.WriteLine(manager.CotrProxy.BaseDirectory);
                Console.WriteLine(manager.CotrProxy.ShadowCopyFiles);
                Console.WriteLine("");
            }

            Console.ReadLine();
        }
    }
}

using Kernel.Interface;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Security.Policy;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Kernel.ServiceAgent
{
    public class ServiceManager<T> : IDisposable where T : class
    {
        private AppDomain ctorProxy = null;

        /// <summary>
        /// 应用程序运行域容器
        /// </summary>
        public AppDomain CotrProxy
        {
            get { return ctorProxy; }
        }

        private T proxy = default(T);

        public T Proxy
        {
            get
            {
                if (proxy == null)
                {
                    proxy = (T)InitProxy(AssemblyPlugs);
                }
                return proxy;
            }
        }

        private string assemblyPlugs;

        /// <summary>
        /// 外挂插件程序集目录路径
        /// </summary>
        public string AssemblyPlugs
        {
            get {
                assemblyPlugs = ConfigHelper.GetVaule("PrivatePath");
                if (assemblyPlugs.Equals("")){
                    assemblyPlugs = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Plugins");
                }
                if (!Directory.Exists(assemblyPlugs)) 
                {
                    Directory.CreateDirectory(assemblyPlugs);
                }
                return assemblyPlugs;
            }
            set { assemblyPlugs = value; }
        }

        public ServiceManager()
        {
            if (proxy == null)
            {
                proxy = (T)InitProxy(AssemblyPlugs);
            }
        }

        private T InitProxy(string assemblyPlugs)
        {
            try
            {
                //AppDomain.CurrentDomain.SetShadowCopyFiles();
                //Get and display the friendly name of the default AppDomain.
                //string callingDomainName = Thread.GetDomain().FriendlyName;

                //Get and display the full name of the EXE assembly.
                //string exeAssembly = Assembly.GetEntryAssembly().FullName;
                //Console.WriteLine(exeAssembly);

                AppDomainSetup ads = new AppDomainSetup();
                ads.ApplicationName = "Shadow";

                //应用程序根目录
                ads.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory;

                //子目录（相对形式）在AppDomainSetup中加入外部程序集的所在目录，多个目录用分号间隔
                ads.PrivateBinPath = assemblyPlugs;

                ads.CachePath = ads.ApplicationBase;
                ads.ShadowCopyFiles = "true";
                ads.ShadowCopyDirectories = ads.ApplicationBase;

                ads.DisallowBindingRedirects = false;
                ads.DisallowCodeDownload = true;
                
                ads.ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;

                //Create evidence for the new application domain from evidence of
                Evidence adevidence = AppDomain.CurrentDomain.Evidence;
                
                // Create the second AppDomain.
                ctorProxy = AppDomain.CreateDomain("AD #2", adevidence, ads);
                
                //Type.GetType("Kernel.TypeLibrary.MarshalByRefType").Assembly.FullName
                string assemblyName = Assembly.GetExecutingAssembly().GetName().FullName;
                //string assemblyName = typeof(MarshalByRefType).Assembly.FullName

                // Create an instance of MarshalByRefObject in the second AppDomain. 
                // A proxy to the object is returned.

                Console.WriteLine("CtorProxy:" + Thread.GetDomain().FriendlyName);

                //TransparentFactory factory = (IObjcet)ctorProxy.CreateInstance("Kernel.TypeLibrary",
　　　　　　　　　　　　　　 "Kernel.TypeLibrary.TransparentFactory").Unwrap();
                TransparentAgent factory = (TransparentAgent)ctorProxy.CreateInstanceAndUnwrap(assemblyName, 
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　typeof(TransparentAgent).FullName);
                
                Type meetType = typeof(T);
                string typeName = AssemblyHelper.CategoryInfo(meetType);

                object[] args = new object[0];
                string assemblyPath = ctorProxy.SetupInformation.PrivateBinPath;

                //IObjcet ilive = factory.Create(@"E:\Plug\Kernel.SimpleLibrary.dll", "Kernel.SimpleLibrary.PlugPut", args);
                T obj = factory.Create<T>(assemblyPath, typeName, args);

                return obj;
            }
            catch (System.Exception)
            {
                throw;
            }
        }

        /// <summary>
        /// 卸载应用程序域
        /// </summary>
        public void Unload()
        {
            try
            {
                if (ctorProxy != null)
                {
                    AppDomain.Unload(ctorProxy);
                    ctorProxy = null;
                }
            }
            catch(Exception)
            {
                throw;
            }
        }

        public void Dispose()
        {
            this.Unload();
        }
    }
}

using Kernel.Interface;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace Kernel.ServiceAgent
{
    public class TransparentAgent : MarshalByRefObject
    {
        private const BindingFlags bfi = BindingFlags.Instance | BindingFlags.Public | BindingFlags.CreateInstance;

        public TransparentAgent() { }

        /// <summary> Factory method to create an instance of the type whose name is specified,
        /// using the named assembly file and the constructor that best matches the specified parameters. </summary>
        /// <param name="assemblyFile"> The name of a file that contains an assembly where the type named typeName is sought. </param>
        /// <param name="typeName"> The name of the preferred type. </param>
        /// <param name="constructArgs"> An array of arguments that match in number, order,
　　　　 /// and type the parameters of the constructor to invoke, or null for default constructor. </param>
        /// <returns> The return value is the created object represented as IObjcet. </returns>
        public IObjcet Create(string assemblyFile, string typeName, object[] args)
        {
            return (IObjcet)Activator.CreateInstanceFrom(assemblyFile, typeName, false, bfi, null, args, null, null).Unwrap();
        }

        public T Create<T>(string assemblyPath, string typeName, object[] args)
        {
            string assemblyFile = AssemblyHelper.LoadAssemblyFile(assemblyPath, typeName);
            return (T)Activator.CreateInstanceFrom(assemblyFile, typeName, false, bfi, null, args, null, null).Unwrap();
        }
    }
}

using Kernel.Interface;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Kernel.ServiceAgent
{
    public class AssemblyHelper
    {
        /// <summary>
        /// 获取泛型类中指定属性值
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public static string CategoryInfo(Type meetType)
        {
            object[] attrList = meetType.GetCustomAttributes(typeof(CategoryInfoAttribute), false);
            if (attrList != null)
            {
                CategoryInfoAttribute categoryInfo = (CategoryInfoAttribute)attrList[0];
                return categoryInfo.Category;
            }
            return "";
        }

        public static string LoadAssemblyFile(string assemblyPlugs, string typeName)
        {
            string path = string.Empty;
            DirectoryInfo d = new DirectoryInfo(assemblyPlugs);
            foreach (FileInfo file in d.GetFiles("*.dll"))
            {
                Assembly assembly = Assembly.LoadFile(file.FullName);
                Type type = assembly.GetType(typeName, false);
                if (type != null)
                {
                    path = file.FullName;
                }
            }
            return path;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;

namespace Kernel.ServiceAgent
{
    public class ConfigHelper
    {
        public static string GetVaule(string configName)
        {
            string configVaule = ConfigurationManager.AppSettings[configName];
            if (configVaule != null && configVaule != "")
            {
                return configVaule.ToString();
            }
            return "";
        }
    }
}

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
    </startup>
    <appSettings>
      <add key="PrivatePath" value="E:\Plugins"/>
    </appSettings>
</configuration>

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

namespace Kernel.Interface
{
    [CategoryInfo("Kernel.SimpleLibrary.PlugPut", "")]
    public interface IObjcet
    {
        void Put();

        string Put(string plus);
    }
}

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

namespace Kernel.Interface
{
    /// <summary>
    /// 设置接口实现类自定义标注属性
    /// </summary>
    /// 
   [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, Inherited = false, AllowMultiple = false)]
    public class CategoryInfoAttribute : Attribute
    {
        public string Category { get; set; }

        public string Describtion { get; set; }

        /// <summary>
        /// 设置实现类自定义标注属性
        /// </summary>
        /// <param name="category"></param>
        /// <param name="describtion"></param>
        public CategoryInfoAttribute(string category, string describtion)
        {
            this.Category = category;
            this.Describtion = describtion;
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Kernel.Interface;

namespace Kernel.SimpleLibrary
{
    [Serializable]
    public class PlugPut : MarshalByRefObject, IObjcet
    {

        private string plugName = "my plugName value is default!";

        public string PlugName
        {
            get { return plugName; }
            set { plugName = value; }
        }

        public PlugPut() { }
             

        public PlugPut(string plusName) 
        {
            this.PlugName = plusName;
        }

        public void Put()
        {
            Console.WriteLine("Default plug value is:" + plugName);
        }

        public string Put(string plus)
        {
            Console.WriteLine("Put plus value is:" + plus);
            return ("-------------------- PlugPut result info is welcome -------------------------");
        }
    }
}