C#插件入门

（一）建立接口类库IDialog,添加接口文件IShowDialog.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
 
namespace IDialog
{
    public interface IShowDialog
    {
        void ShowMyDialog();
 
    }
}

(二）新建插件，添加类库Dialog,实现接口IDalog类Dialog,添加IDialog接口类库的引用就不必多说了

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using IDialog;
 
namespace Dialog
{
    public class Dialog:Form,IShowDialog
    {
 
        public void ShowMyDialog()
        {
            Form frmMyForm = new Form();
            frmMyForm.Text = "Hello World";
            frmMyForm.Show();
        }
    }
}


（三）建立Form应用程序，装载插件Dialog，并显示插件，添加ListBox用来显示插件的名字，
两个Button控件，btnLoadPlugs用来装载插件，btnRunPlugs用来运行插件

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.Collections;
using System.Reflection;
using System.IO;
 
 
namespace MainInvokePlugins
{
    public partial class frmMain : Form
    {
        public frmMain()
        {
            InitializeComponent();
        }
 
 
        private ArrayList listPlugs = new ArrayList();
        private void btnLoadPlugs_Click(object sender, EventArgs e)
        {
            string []files= Directory.GetFiles(Application.StartupPath);
 
            try
            {
 
 
                foreach (string item in files)
                {
                    if (item.ToUpper().EndsWith(".DLL"))
                    {
                        Assembly a = Assembly.LoadFile(item);
                        Type[] ts = a.GetTypes();
                        foreach (Type t in ts)
                        {
                            if (t.GetInterface("IShowDialog") != null)
                            {
                                listPlugs.Add(a.CreateInstance(t.FullName));
                                this.listNames.Items.Add(a.FullName);
                                ;
 
                            }
 
                        }
 
 
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                        
 
            }
            
                
            
        }
 
        private void btnRunPlugs_Click(object sender, EventArgs e)
        {
            if (this.listNames.SelectedIndex==-1)
            {
                return;
            }
            else
            {
                try
                {
                    object plug = this.listPlugs[this.listNames.SelectedIndex];
                    Type t = plug.GetType();
                    MethodInfo showDialog = t.GetMethod("ShowMyDialog");
                    showDialog.Invoke(plug, null);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }
    }
}