.NET插件技术-应用程序热升级

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

namespace PluginDemo
{
    public interface IPlugin
    {
        int GetInt();

        string GetString();
        
        object GetNonMarshalByRefObject();

        Action GetAction();

        List<string> GetList();
    }
}

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

namespace PluginDemo.NewDomain
{

    /// <summary>
    /// 支持跨应用程序域访问
    /// </summary>
    public class Plugin : MarshalByRefObject, IPlugin
    {
        // AppDomain被卸载后，静态成员的内存会被释放掉
        private static int length;

        /// <summary>
        /// int 作为基础数据类型, 是持续序列化的.
        /// <para>在与其他AppDomain通讯时，传递的是对象副本（通过序列化进行的值封送）</para>
        /// </summary>
        /// <returns></returns>
        public int GetInt()
        {
            length += new Random().Next(10000);

            return length;
        }


        /// <summary>
        /// string 作为特殊的class, 也是持续序列化的.
        /// <para>在与其他AppDomain通讯时，传递的是对象副本（通过序列化进行的值封送）</para>
        /// </summary>
        /// <returns></returns>
        public string GetString()
        {
            return "iqingyu";
        }



        /// <summary>
        /// 未继承 MarshalByRefObject 并且 不支持序列化 的 class, 是不可以跨AppDomain通信的，也就是说其他AppDomain是获取不到其对象的
        /// </summary>
        /// <returns></returns>
        public object GetNonMarshalByRefObject()
        {
            return new NonMarshalByRefObject();
        }

        private NonMarshalByRefObjectAction obj = new NonMarshalByRefObjectAction();

        /// <summary>
        /// 委托，和 委托所指向的类型相关
        /// <para>也就是说，如果其指向的类型支持跨AppDomain通信，那个其他AppDomain就可以获取都该委托， 反之，则不能获取到</para>
        /// </summary>
        /// <returns></returns>
        public Action GetAction()
        {
            obj.Add();
            obj.Add();
            //obj.Add();

            return obj.TestAction;
        }

        private List<string> list = new List<string>() { "A", "B" };

        /// <summary>
        /// List<T> 也是持续序列化的, 当然前提是T也必须支持跨AppDomain通信
        /// <para>在与其他AppDomain通讯时，传递的是对象副本（通过序列化进行的值封送）</para>
        /// </summary>
        /// <returns></returns>
        public List<string> GetList()
        {
            return this.list;
            // return new List<Action>() { this.GetAction() };
        }

    }


}

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

namespace PluginDemo.NewDomain
{
    /// <summary>
    /// 未继承 MarshalByRefObject，  不可以跨AppDomain交换消息
    /// </summary>
    public class NonMarshalByRefObject
    {

    }
}

using System;
using System.Windows;
using System.Diagnostics;
using System.Runtime.Serialization.Formatters.Binary;

namespace PluginDemo
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        private AppDomain domain;
        private IPlugin remoteIPlugin;



        public MainWindow()
        {
            InitializeComponent();
        }

        private void loadBtn_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                unLoadBtn_Click(sender, e);

                this.txtBlock.Text = string.Empty;

                // 在新的AppDomain中加载 RemoteCamera 类型
                AppDomainSetup objSetup = new AppDomainSetup();
                objSetup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory;
                objSetup.ShadowCopyFiles = "true";

                // 虽然此方法已经被标记为过时方法， msdn备注也提倡不使用该方法，
                // 但是 以.net 4.0 + win10环境测试，还必须调用该方法 否则，即便卸载了应用程序域 dll 还是未被解除锁定
                AppDomain.CurrentDomain.SetShadowCopyFiles();

                this.domain = AppDomain.CreateDomain("RemoteAppDomain", null, objSetup);
                this.remoteIPlugin = this.domain.CreateInstance("PluginDemo.NewDomain", "PluginDemo.NewDomain.Plugin").Unwrap() as IPlugin;

                this.txtBlock.AppendText("创建AppDomain成功\r\n\r\n");
            }
            catch (Exception ex)
            {
                this.txtBlock.AppendText(ex.Message);
                this.txtBlock.AppendText("\r\n\r\n");
            }
        }

        private void unLoadBtn_Click(object sender, RoutedEventArgs e)
        {
            if (this.remoteIPlugin != null)
            {
                this.remoteIPlugin = null;
            }

            if (this.domain != null)
            {
                AppDomain.Unload(this.domain);
                this.domain = null;
                this.txtBlock.AppendText("卸载AppDomain成功\r\n\r\n");
            }
        }



        private void invokeBtn_Click(object sender, RoutedEventArgs e)
        {
            if (this.remoteIPlugin == null)
                return;

            this.txtBlock.AppendText($"GetInt():{ this.remoteIPlugin.GetInt().ToString()}\r\n");
            this.txtBlock.AppendText($"GetString():{ this.remoteIPlugin.GetString().ToString()}\r\n");


            try
            {
                this.remoteIPlugin.GetNonMarshalByRefObject();
            }
            catch (Exception ex)
            {
                this.txtBlock.AppendText($"GetNonMarshalByRefObject():{ ex.Message}\r\n");
                if (Debugger.IsAttached)
                {
                    Debugger.Break();
                }
            }          
        }
    }
}