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c#eventsfilesystemwatcher

c# FileSystemWatcher - Raising hundreds of unwanted excessive events every several seconds


I am using a FileSystemWatcher class and I need it to monitor my plugged flash drives for any created or pasted files from anywhere. I refresh my list of plugged drives every 2 seconds (in case of any new plugged arrived drives), then setting FileSystemWatcher.EnableRaisingEvents = true, then after 2 seconds I set it to "false", then again refresh plugged drives list etc.

When the refreshing interval is 2 sec, the situation is the following:

  1. The program works for 1 second and I paste the file to the flash drive - FSW raises ONE "Created" event.
  2. The program works for 3 seconds and I paste the file to the flash drive - FSW raises TWO "Created" events.
  3. The program works for 5 seconds and I paste the file to the flash drive - FSW raises THREE "Created" events.
  4. The program works for a couple of minutes and I paste the file to the flash drive - FSW raises A HUNDRED (approximately) "Created" events.

BUT! When the refreshing interval is 30 sec, the situation is the following:

  1. The program works for 1 second and I paste the file to the flash drive - FSW raises ONE "Created" event.
  2. The program works for 3 seconds and I paste the file to the flash drive - FSW raises ONE "Created" event.
  3. The program works for 40 seconds and I paste the file to the flash drive - FSW raises TWO "Created" events.

It is obvious that the problem hosts in the fact, that the FileSystemWatcher is not cleared itself properly and that "not-happened-events" are somehow accumulating in it, then they appear all together when the "Created" event really occurs.

It is necessary to keep refreshing interval low (about 2-3-5 sec). I cannot raise it to several minutes.

Please help. I am stuck with it for six hours. Thanks. Sorry for my English, it's not native.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Management;
using System.Diagnostics;
using System.Collections.Specialized;
using System.Runtime.InteropServices;
using System.Threading;

private static FileSystemWatcher watcher1 = new FileSystemWatcher();

private static DriveInfo[] GetDrivesList()
    {
        DriveInfo[] DriveList = DriveInfo.GetDrives();
        return DriveList;
    }

static bool IsFileLocked(FileInfo file)
    {
        FileStream stream = null;

        if (is_directory == false)
        {
            try
            {
                stream = file.Open(FileMode.Open, FileAccess.ReadWrite, FileShare.None);
            }
            catch (IOException)
            {
                return true;
            }
            finally
            {
                if (stream != null)
                    stream.Close();
            }
        }

        return false;
    }

    static void OnChanged(Object source, FileSystemEventArgs e)
    {
        FileInfo fileInfo = new FileInfo(e.FullPath);
        FileInfo fileInfo2 = new FileInfo(@"D:\Shadow Copies.log");

        if (Convert.ToString(e.ChangeType) == "Created")
        {
            Console.WriteLine("File: {0} has been {1}", e.FullPath, e.ChangeType);
            file_copied = false;

            int length = Convert.ToString(e.FullPath).Length;
            String Path = "";
            String FileName = "";
            for (int i = length - 1; i >= 0; i--)
            {
                if (Convert.ToString(e.FullPath)[i] != '\\')
                {
                    Path += Convert.ToString(e.FullPath)[i];
                }
                else
                {
                    break;
                }
            }
            for (int i = Path.Length - 1; i >= 0; i--)
            {
                FileName += Path[i];
            }

            for (int i = FileName.Length - 1; i >= 0; i--)
            {
                if (FileName[i] == '.')
                {
                    is_directory = false;
                    break;
                }
            }

            string path = Convert.ToString(e.FullPath);

            while (IsFileLocked(fileInfo) == true)
            {
                Thread.Sleep(100);
                Console.WriteLine("Retrying in 1 sec...");
            }

            ProcessStartInfo psi = new ProcessStartInfo();
            psi.CreateNoWindow = true;
            psi.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
            psi.FileName = "cmd.exe";
            psi.Arguments = @"/c xcopy " + path + @" D:\ShadowCopies\ /s /y";
            Process proc = Process.Start(psi);

            file_copied = true;
            Console.WriteLine("File: {0} has been Copied", e.FullPath);
            DateTime datetime = DateTime.Now;

            CandidateLine = e.FullPath;
            write_to_log = String.Format("{0} File: {1} has been Copied\r\n", datetime.ToString(), e.FullPath);
            if (CandidateLine == LastLineWritten)
                return;
            while (IsFileLocked(fileInfo2) == true)
            {
                Thread.Sleep(100);
                Console.WriteLine("Retrying...");
            }
            File.AppendAllText(@"D:\Shadow Copies.log", write_to_log);
            LastLineWritten = CandidateLine;

            is_directory = true;

            ProcessStartInfo psi2 = new ProcessStartInfo();
            psi2.CreateNoWindow = true;
            psi2.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
            psi2.FileName = "cmd.exe";
            psi2.Arguments = "/c for /d %F in (D:\\ShadowCopies\\*) do rd /s /q %F";
            Process proc2 = Process.Start(psi2);
        }
    }

private static void WatchersInitialize()
    {
        DriveInfo[] DriveList = GetDrivesList();
        string[] DriveListArray = new string[DriveList.Length - 1];

        for (int i = 0; i < DriveListArray.Length; i++)
        {
            DriveListArray[i] = DriveList[i + 1].Name;
        } 

            watcher1.IncludeSubdirectories = true;
            watcher1.Path = DriveListArray[drive_position];
            watcher1.NotifyFilter = NotifyFilters.Attributes | NotifyFilters.CreationTime |
            NotifyFilters.DirectoryName | NotifyFilters.FileName |
            NotifyFilters.LastWrite | NotifyFilters.Security | NotifyFilters.Size;
            watcher1.Changed += new FileSystemEventHandler(OnChanged);
            watcher1.Created += new FileSystemEventHandler(OnChanged);
            watcher1.EnableRaisingEvents = true;
    return 0;
 }

static void Main(string[] args)
    {
        while (true)
        {
            watcher1.EnableRaisingEvents = false;
            watcher2.EnableRaisingEvents = false;
            watcher3.EnableRaisingEvents = false;
            watcher4.EnableRaisingEvents = false;
            watcher5.EnableRaisingEvents = false;
            WatchersInitialize();
            Thread.Sleep(2000);
        }
    }

Solution

  • Where you attach the event handlers I think you should remove them first to be sure you aren't doubling up on the events being fired.

    watcher1.Changed -= new FileSystemEventHandler(OnChanged);
    watcher1.Created -= new FileSystemEventHandler(OnChanged);
    watcher1.Changed += new FileSystemEventHandler(OnChanged);
    watcher1.Created += new FileSystemEventHandler(OnChanged);