doing file.copy exception thrown cannot access file is being used, code works when debugging when compiled not

Question

There are of course numerous questions similar to mine, but none really answer my problem or pose the question of why it works in debug and not in runtime.

I have made a FileSystemWatcher which waits for a file to be created in a directory on my server. Raises an Event and then picks up the file name that raised it copies it to another directory as a .csv. While debugging step by step everything works when i compile it breaks trying to File.copy().

class Program
{
    public static string AdresaEXD { get; set; }
    public static string AdresaCSV { get; set; }
    public static string IzvorniFajl { get; set; } //source file
    public static string KreiraniFajl { get; set; }// renamed file

    static void Main(string[] args)
    {
        GledanjeFoldera();/ watcher
    }

    static void GledanjeFoldera()
    {
        AdresaEXD = @"H:\CRT_FOR_FIS\EXD";
        AdresaCSV = @"H:\CRT_FOR_FIS\CSV";

        FileSystemWatcher CRT_gledaj = new FileSystemWatcher(AdresaEXD,"*.exd");

        // Making filters 

        CRT_gledaj.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite | NotifyFilters.DirectoryName | NotifyFilters.FileName;

        // create event handler

        CRT_gledaj.Created += new FileSystemEventHandler(ObradaITransformacijaEXD);

        // starting to watch

        CRT_gledaj.EnableRaisingEvents = true;

        // loop

        Console.WriteLine("Ako zelite da prekinete program pritisnite \'q\'.");

        while (Console.ReadLine() != "q");


    }

    private static void ObradaITransformacijaEXD(object source, FileSystemEventArgs e) // 
    {

        // 
        string NoviFajl = e.Name.Remove(e.Name.Length-4,4)+".csv";// new file name

        // create paths
         IzvorniFajl = System.IO.Path.Combine(AdresaEXD, e.Name);
        KreiraniFajl = System.IO.Path.Combine(AdresaCSV, e.Name);


       // copy file to other destination and delete after 
        System.IO.File.Copy(IzvorniFajl, KreiraniFajl, true);
        System.IO.File.Delete(IzvorniFajl);


    }
}

score 1 · Accepted Answer · answered May 12 '16 at 12:54

The problem is that the FileSystemWatcher event fires when the file begins to be created. Try the following:

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

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

        //file is not locked
        return false;
    }

This function returns true if the file is being used. So you can do a loop like this

while (IsFileLocked(new FileInfo(eventArgs.FullPath))) { }

And wait to exit the loop to copy the file

doing file.copy exception thrown cannot access file is being used, code works when debugging when compiled not

1 Answers1