c# Winform热插拔

1.定义接口

 public interface IUltraman
    {
        string UltramanName { get; set; }
        string Name { get; set; }
        string Attack();

    }

2.接口的继承

编译为不同的dll文件

    public class Taro : IUltraman
    {
        private string name = "Taro";
        public string Name { get => name; set => name = value; }
        private string ultramanName = "泰罗atm";
        public string UltramanName { get => ultramanName; set => ultramanName = value; }


        public string Attack()
        {
            return "Taro attack monster";
        }
    }
    
    public class Ace : IUltraman
    {
        private string name = "Ace";
        public string Name { get => name; set => name = value; }
        private string ultramanName = "艾斯atm";
        public string UltramanName { get=> ultramanName; set=> ultramanName = value; }


        public string Attack()
        {
            return "Ace attack monster";
        }
    }
    

3.读取dll文件为字节流

public class FileToMemory
    {

        public static void ToMemory(string fullName,out byte[] fileBytes)
        {
            using (FileStream fs = new FileStream(fullName,FileMode.Open,FileAccess.Read))
            {
                fileBytes = new byte[fs.Length];
                fs.Read(fileBytes, 0, fileBytes.Length);
            }
        }

    }

4.winform中代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Ultraman;

namespace SelectUltraman
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            //开始监视
            StartWatch();
            //加载dll生成button
            LoadButton();
        }


        private void StartWatch()
        {
            //获取program所在的目录
            string root = Path.GetFullPath(Path.Combine(Path.GetDirectoryName(typeof(Program).Assembly.Location)));
            //获取全目录地址
            string fullPath = Path.GetFullPath(Path.Combine(root, "Plugs"));
            //文件夹监视
            var watcher = new FileSystemWatcher(fullPath);
            watcher.EnableRaisingEvents = true;//启动监听
            //采用委托的方式 
            //beginInvoke是线程执行后执行的
            //invoke是立刻执行的
            //当文件夹中新增文件
            watcher.Created += (s,e)=> { this.BeginInvoke(new FileChange(LoadButton)); };
            //当文件夹中删除文件
            watcher.Deleted += (s, e) => { this.BeginInvoke(new FileChange(LoadButton)); };
            //当文件夹中重命名文件
            watcher.Renamed += (s, e) => { this.BeginInvoke(new FileChange(LoadButton)); };
        }

        delegate void FileChange();

        private void LoadButton()
        {
            //情况panel中的控件
            flowLayoutPanel1.Controls.Clear(); 
            //加载插件地址
            List<string> plugPaths = LoadPlugPaths("Plugs");
            IEnumerable<IUltraman> ultramens = plugPaths.SelectMany(p =>
            {
                Assembly plugAssembly = LoadPlugs(p);
                return CreateUltraman(plugAssembly);
            });

            foreach (var ultraman in ultramens)
            {
                Button btn = new Button()
                {
                    Text = ultraman.UltramanName,
                    Tag = ultraman.Name
                };
                btn.Click += button_Click;
                flowLayoutPanel1.Controls.Add(btn);
            }
        }

        private IEnumerable<IUltraman> CreateUltraman(Assembly plugAssembly)
        {
            Type[] types = plugAssembly.GetExportedTypes();
            IEnumerable<Type> allTypes = types.Where(m => !m.IsAbstract);
            foreach (var type in allTypes)
            {
                IUltraman ultraman = Activator.CreateInstance(type) as IUltraman;
                yield return ultraman;
            }
        }

        private Assembly LoadPlugs(string p)
        {
            FileToMemory.ToMemory(p,out byte[] data);
            return Assembly.Load(data);
        }

        private List<string> LoadPlugPaths(string path)
        {
            string root = Path.GetFullPath(Path.Combine(Path.GetDirectoryName(typeof(Program).Assembly.Location)));
            string fullPath = Path.GetFullPath(Path.Combine(root, path));
            string[] files = Directory.GetFiles(fullPath);
            return files.ToList();
        }

        private void button_Click(object sender, EventArgs e)
        {
            Button button = (Button)sender;
            string tag = button.Tag as string;
            string text = GetUltraman(tag);
            MessageBox.Show(text);
        }

        private string GetUltraman(string tag)
        {
            List<string> plugPaths = LoadPlugPaths("Plugs");
            IEnumerable<IUltraman> ultramens = plugPaths.SelectMany(p =>
            {
                Assembly plugAssembly = LoadPlugs(p);
                return CreateUltraman(plugAssembly);
            });

            var ultramen = ultramens.FirstOrDefault(m=>m.Name == tag);
            if (ultramen != null)
            {
                return ultramen.Attack();
            }
            else
            {
                return null;
            }
        }

    }
}