private void dgvList_CellMouseDown(object sender, DataGridViewCellMouseEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                if (e.RowIndex >= 0)
                {

                    if (dgvList.Rows[e.RowIndex].Selected == false)
                    {
                        dgvList.ClearSelection();
                        dgvList.Rows[e.RowIndex].Selected = true;
                    }
                    if (dgvList.SelectedRows.Count == 1 && e.ColumnIndex != -1)
                    {
                        dgvList.CurrentCell = dgvList.Rows[e.RowIndex].Cells[e.ColumnIndex];
                    }
                }
            }
        }