private PartialFileRecord WriteSingleFile(string _filename_wo_ext, int _nr_locks, ComponentManagerType _user, StringBuilder _sb)
        {
            string content       = _sb.ToString();
            string filename_part = _filename_wo_ext + "_" +
                                   ComponentUtils.ComponentManagerTypeToAbbrevEN(_user) + "." +
                                   ParamStructFileExtensions.FILE_EXT_COMPONENTS;

            try
            {
                using (FileStream fs = File.Create(filename_part))
                {
                    byte[] content_B = System.Text.Encoding.UTF8.GetBytes(content);
                    fs.Write(content_B, 0, content_B.Length);
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Error saving partial file: " + filename_part,
                                MessageBoxButton.OK, MessageBoxImage.Error);
            }

            PartialFileRecord record = new PartialFileRecord()
            {
                FileName     = filename_part,
                Manager      = _user,
                LastModified = DateTime.Now,
                NrLocks      = _nr_locks
            };

            return(record);
        }
        // added 07.02.2017
        private bool DeleteSingleFile(string _filename_wo_ext, ComponentManagerType _user)
        {
            string filename_part = _filename_wo_ext + "_" +
                                   ComponentUtils.ComponentManagerTypeToAbbrevEN(_user) + "." +
                                   ParamStructFileExtensions.FILE_EXT_COMPONENTS;

            try
            {
                if (File.Exists(filename_part))
                {
                    File.Delete(filename_part);
                }
                return(true);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Error deleting partial file: " + filename_part,
                                MessageBoxButton.OK, MessageBoxImage.Error);
                return(false);
            }
        }