public void SaveCurrentFile()
        {
            dataGrid1.SelectAllCells();
            dataGrid1.ClipboardCopyMode = DataGridClipboardCopyMode.ExcludeHeader;
            ApplicationCommands.Copy.Execute(null,dataGrid1);
            dataGrid1.UnselectAllCells();
            string result1 = (string)Clipboard.GetData(DataFormats.CommaSeparatedValue);
            Clipboard.Clear();

            var convertTobyte = Encoding.ASCII.GetBytes(result1);
            var stream = new StreamWriter(_filename);
            stream.WriteLine(convertTobyte);
            stream.Close();

        }