private void LoadDataToListView()
        {
            this.Loading = false;
            lvStudQuizData.Items.Clear();
            ListViewItem lvi = null;

            _lviList.Clear();
            foreach (DAO.UDT_StudQuizDataDef sqd in _StudQuizDataList)
            {
                lvi     = new ListViewItem();
                lvi.Tag = sqd;
                DAO.UDT_QuizDef qd = _UDTTransfer.GetQuizDataByID(sqd.QuizID.ToString());
                lvi.Text = qd.QuizName;
                if (sqd.ImplementationDate.HasValue)
                {
                    lvi.SubItems.Add(sqd.ImplementationDate.Value.ToShortDateString());
                }
                else
                {
                    lvi.SubItems.Add("");
                }
                if (sqd.AnalysisDate.HasValue)
                {
                    lvi.SubItems.Add(sqd.AnalysisDate.Value.ToShortDateString());
                }
                else
                {
                    lvi.SubItems.Add("");
                }

                //lvStudQuizData.Items.Add(lvi);
                _lviList.Add(lvi);
            }

            // sort by ImplementationDate descending
            _lviList = (from data in _lviList orderby data.SubItems[colImplementationDate.Index].Text descending select data).ToList();
            lvStudQuizData.Items.AddRange(_lviList.ToArray());
        }