C# can't delete file after streamreader use

Question

I can't seem to be able to delete files after a streamreader use, with a

"file can't be accessed because file is in use"

error in C#.

I may miss something but I don't know what, here is the code :

fileEntries = from fullFilename
    in Directory.EnumerateFiles(@"Data\csv\pending")
    select Path.GetFileName(fullFilename);

i = 1;

foreach (string file in fileEntries)
{
    if(i == 1)
    {
        folder = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName) + @"\Data\csv\done";

        using (System.IO.FileStream fs = System.IO.File.Create(folder + @"\create-user.csv"))
        {

        }

        using (System.IO.StreamWriter files = new System.IO.StreamWriter(folder + @"\create-user.csv", true))
        {
            files.WriteLine(",; prenom; nom; username; pasword; email; question; reponse; GroupID");
        }

        string curfile = @"\create-user-archive.csv";
        if(!(File.Exists(folder + curfile)))
        {
            using (System.IO.StreamWriter files = new System.IO.StreamWriter(folder + @"\create-user-archive.csv", true))
            {
                files.WriteLine(",; prenom; nom; username; pasword; email; question; reponse; GroupID");
            }
        }
    }


    folder = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName) + @"\Data\csv\pending";
    sb = new StringBuilder();

    filef = new System.IO.StreamReader(folder + @"\create-user-" + i + ".csv");
    line = filef.ReadLine();

    while ((line = filef.ReadLine()) != null)
    {
        sb = new StringBuilder();
        sb.AppendLine(line.Substring(0, line.Length));
        folder = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName) + @"\Data\csv\done";
        using (System.IO.StreamWriter files = new System.IO.StreamWriter(folder + @"\create-user.csv", true))
        {
            files.WriteLine(",; " + sb.ToString().Split(';')[1] + ";" + sb.ToString().Split(';')[2] + ";" + sb.ToString().Split(';')[1] + "." + sb.ToString().Split(';')[2] + ";" + GenerateToken(6) + ";" + sb.ToString().Split(';')[3] + ";" + "1" + ";" + "1");
        }

        folder = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName) + @"\Data\csv\done";
        using (System.IO.StreamWriter files = new System.IO.StreamWriter(folder + @"\create-user-archive.csv", true))
        {
            files.WriteLine(",; " + sb.ToString().Split(';')[1] + ";" + sb.ToString().Split(';')[2] + ";" + sb.ToString().Split(';')[1] + "." + sb.ToString().Split(';')[2] + ";" + GenerateToken(6) + ";" + sb.ToString().Split(';')[3] + ";" + "1" + ";" + "1");
        }
    }
    i++;
    sourceFile = System.IO.Path.Combine(@"Data\csv\pending", file);
    File.Delete(sourceFile);
}

shouldn't the file stop being in use after the streamreader is finished? I tried using a function that waits until the file is unlocked to delete the file, but it is infinite, which means there is a never ending process that I must stop, but I don't see which one.

Answer 1

You need to close filef.

Wrapping the code in a using statement will automatically close the reader

using ( System.IO.StreamReader filef = new System.IO.StreamReader(folder + @"\create-user-" + i + ".csv") {
    ....yourcodehere
}

Alternatively, call filef.Close() when you are done with it (before you delete the file)

Answer 2

You have to close the streams you create to dispose the system resources. You can either use the Close method or the using pattern, as the classes implemented IDisposable interface. I would recommend you to the second option.

May have a look to this post: https://stackoverflow.com/a/707339/6244709

Answer 3

You will need to call the following;

filef.Close();

This would go before your delete;

  while ((line = filef.ReadLine()) != null)
            {
                sb = new StringBuilder();
                sb.AppendLine(line.Substring(0, line.Length));
                folder = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName) + @"\Data\csv\done";
                using (System.IO.StreamWriter files = new System.IO.StreamWriter(folder + @"\create-user.csv", true))
                {
                    files.WriteLine(",; " + sb.ToString().Split(';')[1] + ";" + sb.ToString().Split(';')[2] + ";" + sb.ToString().Split(';')[1] + "." + sb.ToString().Split(';')[2] + ";" + GenerateToken(6) + ";" + sb.ToString().Split(';')[3] + ";" + "1" + ";" + "1");
                }

                folder = Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName) + @"\Data\csv\done";
                using (System.IO.StreamWriter files = new System.IO.StreamWriter(folder + @"\create-user-archive.csv", true))
                {
                    files.WriteLine(",; " + sb.ToString().Split(';')[1] + ";" + sb.ToString().Split(';')[2] + ";" + sb.ToString().Split(';')[1] + "." + sb.ToString().Split(';')[2] + ";" + GenerateToken(6) + ";" + sb.ToString().Split(';')[3] + ";" + "1" + ";" + "1");
                }
            }
            i++;
            sourceFile = System.IO.Path.Combine(@"Data\csv\pending", file);
            filef.Close();
            File.Delete(sourceFile);