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.
* **********************************************/

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\");
}


}




}