C# FileSystemWatcher And FTP

Question

I monitor files that are dropped on a ftp via filesystem watcher then move to another dir. Now I trigger the copy off the create event of the filesystem watcher but obviously i

Answer 1

this is a very naive implementation but it suits my purposes, i have seen enough people with this problem on the web so decided to contribute. The implementation is fairly specific to my needs I almost completely unconcerned with changed events given the nature of my problem but people can throw their own code in there if they need to do something different, it really the created which cause the most issues. I havent fully tested this but at first write it looks good

using System;
using System.Collections.Generic;
using System.IO;
using System.Timers;

namespace FolderSyncing
{
    public class FTPFileSystemWatcher 
    {
        private readonly string _path;
        public event FileSystemEventHandler FTPFileCreated;
        public event FileSystemEventHandler FTPFileDeleted;
        public event FileSystemEventHandler FTPFileChanged;

        private Dictionary _createdFilesToCheck;
        private readonly object _lockObject = new object();
        private const int _milliSecondsSinceLastWrite = 5000;
        private const int _createdCheckTimerInterval = 2000;

        private readonly FileSystemWatcher _baseWatcher;

        public FTPFileSystemWatcher(string path, string Filter)
        {
            _path = path;
            _baseWatcher = new FileSystemWatcher(path,Filter);
            SetUpEventHandling();
        }

        public FTPFileSystemWatcher(string path)
        {
            _path = path;
            _baseWatcher = new FileSystemWatcher(path);
            SetUpEventHandling();
        }

        private void SetUpEventHandling()
        {
            _createdFilesToCheck = new Dictionary();
            Timer copyTimer = new Timer(_createdCheckTimerInterval);
            copyTimer.Elapsed += copyTimer_Elapsed;
            copyTimer.Enabled = true;
            copyTimer.Start();
            _baseWatcher.EnableRaisingEvents = true;
            _baseWatcher.Created += _baseWatcher_Created;
            _baseWatcher.Deleted += _baseWatcher_Deleted;
            _baseWatcher.Changed += _baseWatcher_Changed;
        }

        void copyTimer_Elapsed(object sender, ElapsedEventArgs e)
        {
            lock (_lockObject)
            {
                Console.WriteLine("Checking : " + DateTime.Now);
                DateTime dateToCheck = DateTime.Now;
                List toRemove = new List();
                foreach (KeyValuePair fileToCopy in _createdFilesToCheck)
                {
                    FileInfo fileToCheck = new FileInfo(_path + fileToCopy.Key);
                    TimeSpan difference = fileToCheck.LastWriteTime - fileToCopy.Value.Date;
                    fileToCopy.Value.Update(fileToCopy.Value.Date.AddMilliseconds(difference.TotalMilliseconds));
                    if (fileToCopy.Value.Date.AddMilliseconds(_milliSecondsSinceLastWrite) < dateToCheck)
                    {
                        FileSystemEventArgs args = new FileSystemEventArgs(WatcherChangeTypes.Created, _path, fileToCopy.Key);
                        toRemove.Add(fileToCopy.Key);
                        InvokeFTPFileCreated(args);
                    }
                }
                foreach (string removal in toRemove)
                {
                    _createdFilesToCheck.Remove(removal);
                }
            }
        }



        void _baseWatcher_Changed(object sender, FileSystemEventArgs e)
        {
            InvokeFTPFileChanged(e);
        }

        void _baseWatcher_Deleted(object sender, FileSystemEventArgs e)
        {
            InvokeFTPFileDeleted(e);
        }

        void _baseWatcher_Created(object sender, FileSystemEventArgs e)
        {
            if (!_createdFilesToCheck.ContainsKey(e.Name))
            {
                FileInfo fileToCopy = new FileInfo(e.FullPath);
                _createdFilesToCheck.Add(e.Name,new LastWriteTime(fileToCopy.LastWriteTime));
            }
        }

        private void InvokeFTPFileChanged(FileSystemEventArgs e)
        {
            FileSystemEventHandler Handler = FTPFileChanged;
            if (Handler != null)
            {
                Handler(this, e);
            }
        }

        private void InvokeFTPFileDeleted(FileSystemEventArgs e)
        {
            FileSystemEventHandler Handler = FTPFileDeleted;
            if (Handler != null)
            {
                Handler(this, e);
            }
        }

        private void InvokeFTPFileCreated(FileSystemEventArgs e)
        {
            FileSystemEventHandler Handler = FTPFileCreated;
            if (Handler != null)
            {
                Handler(this, e);
            }
        }
    }

    public class LastWriteTime
    {
        private DateTime _date;

        public DateTime Date
        {
            get { return _date; }
        }

        public LastWriteTime(DateTime date)
        {
            _date = date;
        }

        public void Update(DateTime dateTime)
        {
            _date = dateTime;
        }



    }
}