C#实现插件式开发的一个Demo分享

做winform程序，很多时候都需要用到插件式的，所以本人做了一个Demo，思路跟网上思路基本一致，现在共享出来如有需要的朋友可以下载。

申明：部分代码来源于网上,当然思路也是，呵呵

原理很简单：

一：定义插件接口

二：实现插件接口并建立不同工项目，使其在生成时生成不同的DLL

三：主程序运行时根据接口名利用反射对插件目录的DLL进行加载，加载完成后便可以使用插件接口定义的方法或属性了。

下面上几张图，有兴趣的朋友可以先看看，觉得值得一看的朋友可以下载。

项目结构：

DefaultPlugin,PosPlugin两个项目均为插件，均实现了Iplugin接可

Iplugin接口

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace WinDemo.Core
{
    public interface Iplugin
    {

        PluginInfoAttribute PluginInfo
        { get; set; }
        bool IsLoad
        {
            get;
            set;
        }

        Image ModulePicture
        {
            get;
        }

        Image ModulePictureEnter
        {
            get;
        }

        Image ModulePictureClick
        {
            get;
        }

        string ModuleName
        {
            get;
        }

        Dictionary<string, EventHandler> ChildNodes
        {
            get;
        }

        ILoadForm FormLoader
        {
            get;
            set;
        }


    }
}

用于加载插件的类 PluginLoader

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.IO;
using System.Windows.Forms;
using System.Collections;

namespace WinDemo.Core
{
    public static class PluginLoader
    {

        public static List<Iplugin> plugins = new List<Iplugin>();
        private static ArrayList piProperties = new ArrayList();

        private static bool IsValidPlugin(Type t)
        {
            bool ret = false;
            Type[] interfaces = t.GetInterfaces();
            foreach( Type theInterface in interfaces ) {
                if (theInterface.FullName == "WinDemo.Core.Iplugin")
                {
                    ret = true;
                    break;
                }
            }
            return ret;
        }



        public static void LoadAllPlugins()
        {
            string[] files = Directory.GetFiles(Application.StartupPath + "\\plugin\\");
            int i = 0;
            PluginInfoAttribute typeAttribute = new PluginInfoAttribute();
            foreach (string file in files)
            {
                string ext = file.Substring(file.LastIndexOf("."));
                if (ext != ".dll") continue;
                try
                {
                    Assembly tmp = Assembly.LoadFile(file);
                    Type[] types = tmp.GetTypes();
                    bool ok = false;
                    foreach (Type t in types)
                        if (IsValidPlugin(t))
                        {
                            Iplugin plugin = (Iplugin)tmp.CreateInstance(t.FullName);
                            plugins.Add(plugin);
                            object[] attbs = t.GetCustomAttributes(typeAttribute.GetType(), false);
                            PluginInfoAttribute attribute = null;
                            foreach (object attb in attbs)
                            {
                                if (attb is PluginInfoAttribute)
                                {
                                    attribute = (PluginInfoAttribute)attb;
                                    attribute.Index = i;
                                    i++;
                                    ok = true;
                                    break;
                                }
                            }

                            if (attribute != null)
                            {
                                piProperties.Add(attribute);
                                plugin.PluginInfo = attribute;
                            }
                            else throw new Exception("未定义插件属性");
                            if (ok) break;
                        }
                }
                catch (Exception err)
                {
                    throw err;
                }
            }
            plugins.Sort((p1, p2) => {
                return p2.PluginInfo.Index - p1.PluginInfo.Index;
            });
        }
    }
}

Iplugin的实现类PosPlugin类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using WinDemo.Core;
using System.Windows.Forms;

namespace DefaultPlugin
{
    [PluginInfo("Default","1.0","XH","www.cnporter.com",true,2)]
    public class Default : WinDemo.Core.Iplugin
    {
        private Dictionary<string, EventHandler> _ChildNodes = new Dictionary<string, EventHandler>();
        private LeftNav frmLeftNav = new LeftNav();
        public static ILoadForm Formloader ;
        public Default()
        {

            _ChildNodes.Add("菜单五", (sender,e) =>
            {
                MessageBox.Show(sender.ToString());
            });
            _ChildNodes.Add("菜单四", (sender, e) =>
            {
                MessageBox.Show(sender.ToString());
            });
            _ChildNodes.Add("菜单三", (sender, e) =>
            {
                MessageBox.Show(sender.ToString());
            });
            _ChildNodes.Add("菜单二", (sender, e) =>
            {
                MessageBox.Show(sender.ToString());
            });
            _ChildNodes.Add("菜单一", (sender, e) =>
            {
                FormLoader.LoadNavFrm(frmLeftNav);
            });
        }



        public Image ModulePicture
        {
            get
            {
                return ((System.Drawing.Image)(ImageResource.Index));
            }
        }

        public Image ModulePictureEnter
        {
            get
            {
                return ((System.Drawing.Image)(ImageResource.IndexEnter));
            }
        }

        public Image ModulePictureClick
        {
            get
            {
                return ((System.Drawing.Image)(ImageResource.IndexClick));
            }
        }

        public string ModuleName
        {
            get
            {
                return "首页";
            }
        }

        public Dictionary<string, EventHandler> ChildNodes
        {
            get
            {
                return _ChildNodes;
            }
        }

        public bool IsLoad
        {
            get;
            set;
        }

        public ILoadForm FormLoader
        {
            get
            {
                return Formloader;
            }
            set
            {
                Formloader = value;
            }
        }

        public PluginInfoAttribute PluginInfo
        {
            get;
            set;
        }
    }

}

此图现在有两个插件