Csharp/CSharp Tutorial/File Directory Stream/FileSystemWatcher

FileSystemWatcher Demo

using System;
using System.IO;
public class MainClass
{
    public static void Main(string[] args)
    {
         FileSystemWatcher watcher = new FileSystemWatcher();
         watcher.Path = @"c:\Test";
         watcher.NotifyFilter  = NotifyFilters.LastAccess |
                                 NotifyFilters.LastWrite |
                                 NotifyFilters.FileName |
                                 NotifyFilters.DirectoryName;
         watcher.Filter = "*.txt";
         watcher.Changed += new FileSystemEventHandler(OnChanged);
         watcher.Created += new FileSystemEventHandler(OnChanged);
         watcher.Deleted += new FileSystemEventHandler(OnChanged);
         watcher.Renamed += new RenamedEventHandler(OnRenamed);
         watcher.EnableRaisingEvents = true;
                     
    }
    
    public static void OnChanged(object source, FileSystemEventArgs e)
    {
           Console.WriteLine("Event Fired");
    }
    public static void OnRenamed(object source, RenamedEventArgs e)
    {
        Console.WriteLine("Event Fired");
    }
}

File Watch

using System;
using System.Collections.Generic;
using System.ruponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
    public class Form1 : Form
    {
        private FileSystemWatcher watcher;
        private delegate void UpdateWatchTextDelegate(string newText);
        public Form1()
        {
            InitializeComponent();
            this.watcher = new System.IO.FileSystemWatcher();
            this.watcher.Deleted += new System.IO.FileSystemEventHandler(this.OnDelete);
            this.watcher.Renamed += new System.IO.RenamedEventHandler(this.OnRenamed);
            this.watcher.Changed += new System.IO.FileSystemEventHandler(this.OnChanged);
            this.watcher.Created += new System.IO.FileSystemEventHandler(this.OnCreate);
            DirectoryInfo aDir = new DirectoryInfo("C:\\");
        }
        public void UpdateWatchText(string newText)
        {
            lblWatch.Text = newText;
        }
        public void OnChanged(object source, FileSystemEventArgs e)
        {
            try
            {
                StreamWriter sw = new StreamWriter("C:/Log.txt", true);
                sw.WriteLine("File: {0} {1}", e.FullPath,e.ChangeType.ToString());
                sw.Close();
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Wrote change event to log");
            }
            catch (IOException)
            {
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Error Writing to log");
            }
        }
        public void OnRenamed(object source, RenamedEventArgs e)
        {
            try
            {
                StreamWriter sw = new StreamWriter("C:/Log.txt", true);
                sw.WriteLine("File renamed from {0} to {1}", e.OldName,e.FullPath);
                sw.Close();
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Wrote renamed event to log");
            }
            catch (IOException)
            {
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Error Writing to log");
            }
        }
        public void OnDelete(object source, FileSystemEventArgs e)
        {
            try
            {
                StreamWriter sw = new StreamWriter("C:/Log.txt", true);
                sw.WriteLine("File: {0} Deleted", e.FullPath);
                sw.Close();
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Wrote delete event to log");
            }
            catch (IOException)
            {
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Error Writing to log");
            }
        }
        public void OnCreate(object source, FileSystemEventArgs e)
        {
            try
            {
                StreamWriter sw = new StreamWriter("C:/FileLogs/Log.txt", true);
                sw.WriteLine("File: {0} Created", e.FullPath);
                sw.Close();
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Wrote create event to log");
            }
            catch (IOException)
            {
                this.BeginInvoke(new UpdateWatchTextDelegate(UpdateWatchText),"Error Writing to log");
            }
        }
        private void cmdBrowse_Click(object sender, EventArgs e)
        {
            if (FileDialog.ShowDialog() != DialogResult.Cancel)
            {
                txtLocation.Text = FileDialog.FileName;
                cmdWatch.Enabled = true;
            }
        }
        private void cmdWatch_Click(object sender, EventArgs e)
        {
            watcher.Path = Path.GetDirectoryName(txtLocation.Text);
            watcher.Filter = Path.GetFileName(txtLocation.Text);
            watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.Size;
            lblWatch.Text = "Watching " + txtLocation.Text;
            watcher.EnableRaisingEvents = true;
        }
        private void InitializeComponent()
        {
            this.txtLocation = new System.Windows.Forms.TextBox();
            this.cmdBrowse = new System.Windows.Forms.Button();
            this.cmdWatch = new System.Windows.Forms.Button();
            this.lblWatch = new System.Windows.Forms.Label();
            this.FileDialog = new System.Windows.Forms.OpenFileDialog();
            this.SuspendLayout();
            // 
            // txtLocation
            // 
            this.txtLocation.Location = new System.Drawing.Point(8, 26);
            this.txtLocation.Name = "txtLocation";
            this.txtLocation.Size = new System.Drawing.Size(184, 20);
            this.txtLocation.TabIndex = 0;
            // 
            // cmdBrowse
            // 
            this.cmdBrowse.Location = new System.Drawing.Point(208, 24);
            this.cmdBrowse.Name = "cmdBrowse";
            this.cmdBrowse.Size = new System.Drawing.Size(64, 24);
            this.cmdBrowse.TabIndex = 1;
            this.cmdBrowse.Text = "Browse...";
            this.cmdBrowse.UseVisualStyleBackColor = true;
            this.cmdBrowse.Click += new System.EventHandler(this.cmdBrowse_Click);
            // 
            // cmdWatch
            // 
            this.cmdWatch.Enabled = false;
            this.cmdWatch.Location = new System.Drawing.Point(88, 56);
            this.cmdWatch.Name = "cmdWatch";
            this.cmdWatch.Size = new System.Drawing.Size(80, 32);
            this.cmdWatch.TabIndex = 2;
            this.cmdWatch.Text = "Watch!";
            this.cmdWatch.UseVisualStyleBackColor = true;
            this.cmdWatch.Click += new System.EventHandler(this.cmdWatch_Click);
            // 
            // lblWatch
            // 
            this.lblWatch.AutoSize = true;
            this.lblWatch.Location = new System.Drawing.Point(8, 104);
            this.lblWatch.Name = "lblWatch";
            this.lblWatch.Size = new System.Drawing.Size(0, 13);
            this.lblWatch.TabIndex = 3;
            // 
            // FileDialog
            // 
            this.FileDialog.FileName = "openFileDialog1";
            this.FileDialog.Filter = "All Files|*.*";
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(296, 135);
            this.Controls.Add(this.lblWatch);
            this.Controls.Add(this.cmdWatch);
            this.Controls.Add(this.cmdBrowse);
            this.Controls.Add(this.txtLocation);
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
            this.MaximizeBox = false;
            this.MinimizeBox = false;
            this.Name = "Form1";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "File Monitor";
            this.ResumeLayout(false);
            this.PerformLayout();
        }
        private System.Windows.Forms.TextBox txtLocation;
        private System.Windows.Forms.Button cmdBrowse;
        private System.Windows.Forms.Button cmdWatch;
        private System.Windows.Forms.Label lblWatch;
        private System.Windows.Forms.OpenFileDialog FileDialog;
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }

My Directory Watcher

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
  class Program
  {
    static void Main(string[] args)
    {
      FileSystemWatcher watcher = new FileSystemWatcher();
      watcher.Path = "C:\\";
      watcher.NotifyFilter = NotifyFilters.LastAccess
        | NotifyFilters.LastWrite
        | NotifyFilters.FileName
        | NotifyFilters.DirectoryName;
      watcher.Filter = "*.txt";
      watcher.Changed += new FileSystemEventHandler(OnChanged);
      watcher.Created += new FileSystemEventHandler(OnChanged);
      watcher.Deleted += new FileSystemEventHandler(OnChanged);
      watcher.Renamed += new RenamedEventHandler(OnRenamed);
      watcher.EnableRaisingEvents = true;
      Console.Read();
    }
    static void OnChanged(object source, FileSystemEventArgs e)
    {
      Console.WriteLine("File: {0} {1}!", e.FullPath, e.ChangeType);
    }
    static void OnRenamed(object source, RenamedEventArgs e)
    {
      Console.WriteLine("File: {0} renamed to\n{1}", e.OldFullPath, e.FullPath);
    }
  }

Use FileSystemWatcher to detect file changes

using System;
using System.IO;
using System.Windows.Forms;
static class MainClass
{
    static void Main()
    {
        using (FileSystemWatcher watch = new FileSystemWatcher())
        {
            watch.Path = Application.StartupPath;
            watch.Filter = "*.*";
            watch.IncludeSubdirectories = true;
            watch.Created += new FileSystemEventHandler(OnCreatedOrDeleted);
            watch.Deleted += new FileSystemEventHandler(OnCreatedOrDeleted);
            watch.EnableRaisingEvents = true;
            if (File.Exists("test.bin"))
            {
                File.Delete("test.bin");
            }
            using (FileStream fs = new FileStream("test.bin", FileMode.Create))
            {
            }
        }
    }
    private static void OnCreatedOrDeleted(object sender, FileSystemEventArgs e)
    {
        Console.WriteLine("\tNOTIFICATION: " + e.FullPath + "" was " + e.ChangeType.ToString());
    }
}

NOTIFICATION: C:\Java_Dev\WEB\dev\CSharp\test.bin" was Deleted

Watching for filesystem updates synchronous

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.IO;
using System.IO.rupression;
using System.Net;
using System.Net.Mail;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using System.Text;
public class MainClass
{
    public static void Main()
    {
        FileSystemWatcher watcher = new FileSystemWatcher(@"c:\", "*.*");
        // only rename event
        WaitForChangedResult result =watcher.WaitForChanged(WatcherChangeTypes.Changed | WatcherChangeTypes.Renamed);
        switch (result.ChangeType)
        {
            case WatcherChangeTypes.Changed:
                Console.WriteLine("{0}: File "{1}" was changed",DateTime.Now, result.Name);
                break;
            case WatcherChangeTypes.Renamed:
                Console.WriteLine("{0}: File "{1}" was renamed to "{2}"",DateTime.Now, result.OldName, result.Name);
                break;
        }
    }
}