private void backgroundWorker3_DoWork(object sender, DoWorkEventArgs e)
    {

        List<string> result = new List<string>();

        var found = obj.getFiles();//List<strings>
        if (found.Count != 0)
        {

            for (int i = 0; i < found.Count; i++)
            {
                int progress = (int)(((float)(i + 1) / found.Count) * 100);
                if (found[i].Contains("SFTP"))
                {
                    result.Add(found[i]);

                    (sender as BackgroundWorker).ReportProgress(progress, found[i]);
                }
                System.Threading.Thread.Sleep(500);
            }



            e.Result = result;

        }
    }

    private void backgroundWorker3_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        if (e.UserState != null)

        listBox3.Items.Add(e.UserState);

    }