Plugin Architecture using C#

using System.Configuration;
using System;
using System.IO;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using PlugIn;
using System.Reflection;

namespace PluginWindowTest
{
	/// <summary>
	/// Summary description for Form1.
	/// </summary>
	public class Form1 : System.Windows.Forms.Form, IPluginHost
	{
		private System.Windows.Forms.MainMenu mainMenu1;
		private System.Windows.Forms.MenuItem menuItem1;

		private IPlugin[] ipi;

		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		public Form1()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();

			//
			// TODO: Add any constructor code after InitializeComponent call
			//
		}

		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			this.mainMenu1 = new System.Windows.Forms.MainMenu();
			this.menuItem1 = new System.Windows.Forms.MenuItem();
			// 
			// mainMenu1
			// 
			this.mainMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
																					  this.menuItem1});
			// 
			// menuItem1
			// 
			this.menuItem1.Index = 0;
			this.menuItem1.Text = "Plugin";
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(520, 357);
			this.Menu = this.mainMenu1;
			this.Name = "Form1";
			this.Text = "Form1";
			this.Load += new System.EventHandler(this.Form1_Load);

		}
		#endregion

		/// <summary>
		/// The main entry point for the application.
		/// </summary>
		[STAThread]
		static void Main() 
		{
			Application.Run(new Form1());
		}

		private void Form1_Load(object sender, System.EventArgs e)
		{
			string path = Application.StartupPath;
			string[] pluginFiles = Directory.GetFiles(path, "*.dll");
			ipi = new IPlugin[pluginFiles.Length];

			for(int i=0; i<pluginFiles.Length; i++)
			{
				string args = pluginFiles[i].Substring(
					pluginFiles[i].LastIndexOf("\\")+1,
					pluginFiles[i].IndexOf(".dll")-
					pluginFiles[i].LastIndexOf("\\")-1);

				Type ObjType = null;
				//IPlugin ipi;
				// load the dll
				try
				{
					// load it
					Assembly ass = null;
					ass = Assembly.Load(args);
					if (ass != null)
					{
						ObjType = ass.GetType(args+".PlugIn");
					}
				}
				catch (Exception ex)
				{
					Console.WriteLine(ex.Message);
				}
				try
				{
					// OK Lets create the object as we have the Report Type
					if (ObjType != null)
					{
						ipi[i] = (IPlugin)Activator.CreateInstance(ObjType);
						ipi[i].Host = this;
						Console.WriteLine("ipi.Add(1,2)=" + ipi[i].Add(1,2));
					}
				}
				catch (Exception ex)
				{
					Console.WriteLine(ex.Message);
				}

				//				Start(assemname);
			}
			//MessageBox.Show(ConfigurationSettings.AppSettings["App"]);
		}

		public void Start(string args)
		{
			Type ObjType = null;
			IPlugin ipi;
			// load the dll
			try
			{
				// load it
				Assembly ass = null;
				ass = Assembly.Load(args);
				if (ass != null)
				{
					ObjType = ass.GetType(args+".PlugIn");
				}
			}
			catch (Exception ex)
			{
				Console.WriteLine(ex.Message);
			}
			try
			{
				// OK Lets create the object as we have the Report Type
				if (ObjType != null)
				{
					ipi = (IPlugin)Activator.CreateInstance(ObjType);
					ipi.Host = this;
					Console.WriteLine("ipi.Add(1,2)=" + ipi.Add(1,2));
				}
			}
			catch (Exception ex)
			{
				Console.WriteLine(ex.Message);
			}
		}

		public bool Register(IPlugin ipi)
		{
			MenuItem mn = new MenuItem(ipi.Name,new EventHandler(NewLoad));

			Console.WriteLine("Registered: " + ipi.Name);
			menuItem1.MenuItems.Add(mn);
			return true;
		}

		private void NewLoad(object sender, System.EventArgs e)
		{
			MenuItem mn = (MenuItem)sender;

			for(int i=0; i<ipi.Length; i++)
			{
				string strType = mn.Text;
				if(ipi[i]!=null)
				{
					if(ipi[i].Name==strType)
					{
						ipi[i].Show();
						break;
					}
				}
			}			
		}
	}
}