C# 反照实例

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace PlugDemo{    public interface IPlugToText    {        string ProccessText(string text);    }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace PlugDemo{    public class MenuNameAttribute:Attribute    {        private string _name;        public string Name        {            get { return _name; }            set { _name = value; }        }        public MenuNameAttribute(string name)        {            this._name = name;        }    }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ComPlugDemo{    [PlugDemo.MenuName("转小写")]    public class PlugToLower : PlugDemo.IPlugToText    {        #region IPlugToText 成员                public string ProccessText(string text)        {            return text.ToLower();        }        #endregion    }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ComPlugDemo{    [PlugDemo.MenuName("转大写")]    public class PlugToUpper:PlugDemo.IPlugToText    {        #region IPlugToText 成员                public string ProccessText(string text)        {            return text.ToUpper();        }        #endregion    }}

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Reflection;using System.IO;using PlugDemo;namespace 插件Demo{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void Form1_Load(object sender, EventArgs e)        {            AddPlugMenu();        }        void AddPlugMenu()        {            //1、加载正在运行的程序集的物理路径            Assembly ass = this.GetType().Assembly;            string location = ass.Location;            //2、获取 程序集所在文件夹，并转成 插件程序集文件夹的路径            string assDir = Path.GetDirectoryName(location);            string plugDir = assDir + "\\plugs";            //3、扫描 产检文件夹里的 所有程序集文件            string [] dllPaths = Directory.GetFiles(plugDir,"*.dll");            //重点： 获取插件接口 类型对象            //4、遍历程序集文件路径，并加载程序家到内存中            Type iplugType = typeof(IPlugToText);            foreach (string dllPath in dllPaths)            {                //4.1 、根据路径 加载程序集文件 到内存中                Assembly amy = Assembly.LoadFrom(dllPath);                //4.2 、判断程序集中是否有插件类                //4.2.1、获取插件程序集里公有的类                Type[] types = amy.GetExportedTypes();                //4.2.2 循环遍历 插件程序集里的类型 ，判断是否实现记事本插件接口                foreach (Type t in types)                {                    //判断 t 是否 实现了接口 IPlugToUpper                    if (iplugType.IsAssignableFrom(t))                    {                        //重要，获取的MenuNameAttribute 特性对象，或将 内部的Name现在到菜单中                        object[] atts = t.GetCustomAttributes(typeof(MenuNameAttribute),false);                        MenuNameAttribute menuName = atts[0] as MenuNameAttribute;                        //重要：根据插件类型，创建 插件类 对象                        IPlugToText iplug = Activator.CreateInstance(t) as IPlugToText;                        ToolStripMenuItem item = new ToolStripMenuItem(menuName.Name);                        plugMenu.DropDownItems.Add(item);                        item.Click += new EventHandler(item_Click);                        item.Tag = iplug;                    }                 }            }                    }        void item_Click(object sender, EventArgs e)        {            ToolStripMenuItem item = sender as ToolStripMenuItem;            IPlugToText iplug = item.Tag as IPlugToText;            textBox1.Text = iplug.ProccessText(textBox1.Text);        }    }}