Delete file using C# Thread

Question

I was reading this article (Can't delete a file using threads) about my problem but things are getting difficult to me.

My problem is really simple, I just want to delete this old file, if I start the method "dlMoveNovaVersao" normally the file is deleted but if I put this on a thread (like bellow) I got "You are not allow". Someone knows what's the problem? (I wanna use thread).

    private void verificaVersaoSupervisor_Tick(object sender, EventArgs e)
    {
        Thread threadConexao = new Thread(threadVerificaConexao);
        threadConexao.Start();
    }

    public void threadVerificaConexao()
    {
        try
        {
            Dns.GetHostEntry("www.google.com.br");
            if (verificaVersao())
            {
                try
                {
                    verificaKillSupervisor();
                    dlMoveNovaVersao();
                    Application.Exit();
                }
                catch (Exception)
                { }
            }
            else
            {
                Application.Exit(); 
            }
        }
        catch (Exception)
        { }
    }

    public void dlMoveNovaVersao()
    {
        WebClient webClient = new WebClient();
        webClient.DownloadFile("Anywebsite", @"c:\temp\supervisor.exe);
        try
        {
            File.Delete(@"c:\Test\supervisor.exe); //This file is always there!
        }
        catch (Exception err)
        {
            MessageBox.Show(err.Message);
        }

Just discribe the purpose, My program (Supervisor Starter) check on website if I have an old version of "Supervisor" running (using XML), If it's true my "Supervisor Starter" verify if there is a process called "Supervisor" running and kill it after that "Supervisor Starter" download the new version and run it. (The program is small and the update don't take more then 4 seconds).

The problem start when my "Supervisor Starter" try delete the old version of my program. If I use thread I receive "I haven't permission to access the file", if I use the same method on Form class the file is deleted.

Answer 1

I suspect that you're running the thread while the file is in use. When the thread runs, it runs in parallel with the current thread. Have you ensured that that file is closed?.

Otherwise I think that the thread maybe being created with a credentials that are not yours. But I'm pretty sure this is not the case.

See if this is different for each case

catch (Exception err)
    {
        MessageBox.Show("User {0}. Message {1}", 
                         System.Security.Principal.WindowsIdentity.GetCurrent().Name, 
                         err.Message);
    }