Question

I’m trying to write a small utility service that will detect when a item(s) has been added to a synced drop box folder and then wait (to allow full sync) and move item(s) into a date stamped staging folder for further processing. Simple enough …

Here is my code:

    static void Main(string[] args)
    {
        var watcher = new FileSystemWatcher();

        string _path = @"E:\IMPORT\Dropbox\";
        watcher.Path = _path;
        watcher.EnableRaisingEvents = true;
        watcher.Created += new FileSystemEventHandler(watcher_Created);


        Console
         .WriteLine("FileSystemWatcher ready and listening to changes in :\n\n" 
                    + _path);

        watcher.Path = _path;
        Console.ReadLine();
    }

    static void watcher_Created(object sender, FileSystemEventArgs e)
    {
        Thread.Sleep(3000);
        Console.WriteLine(e.Name + " file has been created.");

        string filename = Path.GetFileName(e.FullPath);
        string path = @"E:\IMPORT\Staging\" 
                      + DateTime.Now.ToFileTime().ToString() 
                      + @"\";

        try 
        { 
          Directory.CreateDirectory(path); 
        } 
        catch(Exception ex) 
        { 
          Console.WriteLine("Error: " + ex.ToString()); 
        }
        try 
        { 
          File.Move(e.FullPath, path + filename); 
        } 
        catch(Exception ex) 
        { 
          Console.WriteLine("Error: " + ex.ToString());
        }
    }

This code would work fine if one item was being added to the synced directory, however multiple items will be added and there needs to be a delay for items to be added to the dropbox. Any ideas on how I can accomplish this ?

Answer 1

I think that your best option here is to remove FileSystemWatcher and replace it with your own periodic monitoring of the directory (for example, a loop in a BackgroundWorker thread or a Timer-triggered event).

In this design, you can delay processing of the file for as long as you need by comparing the timestamp on the file with current time and only processing the file when you think that enough time has passed.

This design will also support restarting the application with files already present in the directory which the FileSystemWatcher approach probably will not.