How to use FileSystemWatcher in .Net

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Threading;

namespace PubishApps
{
    public class ClsFileSystemWatcher
    {
    
/************************************************
* Topic : How to use FileSystemWatcher in .Net
* Reference Required: System.IO, System.Threading.
* Author : kalit sikka
* Usage: This class can use to track for filesystem changes on the local machine, a networked drive, and even a remote machine.
* Generally use in window services to track changes in background.
* For : http://eggheadcafe.com
* **********************************************/

    public  void FileWatcher(string InputDir)
    {    
     using (FileSystemWatcher fsw = new FileSystemWatcher( ))
    {
        fsw.Path = InputDir; // Input Path
        fsw.Filter = @"*.txt"; // Filter for files
        fsw.IncludeSubdirectories = true;

        fsw.NotifyFilter = NotifyFilters.FileName |
            NotifyFilters.Attributes  |
            NotifyFilters.LastAccess  |
            NotifyFilters.LastWrite   |
            NotifyFilters.Security    |
            NotifyFilters.Size        |
            NotifyFilters.CreationTime|
            NotifyFilters.DirectoryName;

        fsw.Changed += new FileSystemEventHandler(OnChanged);
        fsw.Created += new FileSystemEventHandler(OnCreated);
        fsw.Deleted += new FileSystemEventHandler(OnDeleted);
        fsw.Renamed += new RenamedEventHandler(OnRenamed);
        fsw.Error += new ErrorEventHandler(OnError);

        fsw.EnableRaisingEvents = true;

        string strOldFile = InputDir + "OldFile.txt";
        string strNewFile = InputDir + "CreatedFile.txt";

        // Making changes in existing file
        
         using (FileStream stream = File.Open(strOldFile, FileMode.Append))
        {
            StreamWriter sw = new StreamWriter(stream);
             sw.Write("Appending new line in Old File");
            sw.Flush();
            sw.Close();
            
        }

         // Writing new file on FileSystem
        
         using (FileStream stream = File.Create(strNewFile))
        {
            StreamWriter sw = new StreamWriter(stream);
             sw.Write("Writing First line into the File");
            sw.Flush();
            sw.Close();
        }

         File.Delete(strOldFile);
         File.Delete(strNewFile);

         
         // Minimum time given to event handler to track new events raised by the filesystem.
      
         Thread.Sleep(1000);
    }
}

    public static void OnChanged(object source, FileSystemEventArgs e)
    {
         Console.WriteLine("File " + e.FullPath + " :" + e.ChangeType);
    }

     public static void OnDeleted(object source, FileSystemEventArgs e)
    {
         Console.WriteLine("File " + e.FullPath + " :" + e.ChangeType);
    }

     public static void OnCreated(object source, FileSystemEventArgs e)
    {
         Console.WriteLine("File " + e.FullPath + " :" + e.ChangeType);
    }

     public static void OnRenamed(object source, RenamedEventArgs e)
    {
         Console.WriteLine("File " + e.OldFullPath + " [Changed to] " + e.FullPath);
    }

    public static void OnError(object source, ErrorEventArgs e)
    {
         Console.WriteLine("Error " + e.ToString( ));
    }
         
        
        
         static void Main(string[] args)
        {
            ClsFileSystemWatcher FSysWatcher = new ClsFileSystemWatcher();
             FSysWatcher.FileWatcher(@"D:\kalit\");
         }
    
    
    }

     


}