Get Multi row in Single Coloum using C#.Net Code

Get Value from Dataset and assign to Gridview:

public string strTransactionNumber1 = "";
public string strTransactionNumber2 = "";
public string strSeatNo = "";

DataTable dtData = new DataTable();
dtData.Columns.Add("TransactionNumber");
dtData.Columns.Add("UserName");
dtData.Columns.Add("TransactionDate");
dtData.Columns.Add("ShowDate");
dtData.Columns.Add("ShowTime");
dtData.Columns.Add("MovieName");
dtData.Columns.Add("SeatName");
dtData.Columns.Add("TotalTickets");
dtData.Columns.Add("Per Seat Price");
dtData.Columns.Add("Limata Amount");
dtData.Columns.Add("Client Amount");
dtData.Columns.Add("Name");
dtData.Columns.Add("MobileNumber");
dtData.Columns.Add("EmailID");
dtData.Columns.Add("IDCardType");
dtData.Columns.Add("IDCardInfo");
DataTable dt = new DataTable();

DataSet dsReport = new DataSet();
OtherBLL objReport = new OtherBLL();
dsReport = objReport.GetTheatreReport(Convert.ToDateTime(txtStartDate.Text), Convert.ToDateTime(txtEndDate.Text), 146, ddlShowTime.SelectedItem.Text);
if (dsReport.Tables[0].Rows.Count > 0)
{
for (int i = 0; i < dsReport.Tables[0].Rows.Count; i++)
{

dt = dsReport.Tables[0];
DataRow dr;
dr = dtData.NewRow();
if (i > 0)
strTransactionNumber1 = dt.Rows[i - 1]["V_TransactionNumber"].ToString();
strTransactionNumber2 = dt.Rows[i]["V_TransactionNumber"].ToString();

if (strTransactionNumber1 == strTransactionNumber2)
{
strSeatNo += "," + dt.Rows[i]["V_SeatName"].ToString();
}
else
{
strSeatNo = dt.Rows[i]["V_SeatName"].ToString();
}
dtData.Rows.Add(dt.Rows[i]["V_TransactionNumber"].ToString(), dt.Rows[i]["V_UserName"].ToString(), dt.Rows[i]["D_TransactionDate"].ToString(), dt.Rows[i]["D_ShowDate"].ToString(), dt.Rows[i]["V_ShowTime"].ToString(), dt.Rows[i]["V_MovieName"].ToString(), strSeatNo, dt.Rows[i]["N_TotalTickets"].ToString(), dt.Rows[i]["C_SeatPrice"].ToString(), dt.Rows[i]["LimataAmount"].ToString(), dt.Rows[i]["F_TotalPrice"].ToString(), dt.Rows[i]["V_CardHolderName"].ToString(), dt.Rows[i]["V_MobileNumber"].ToString(), dt.Rows[i]["V_EmailID"].ToString(), dt.Rows[i]["V_IDCardType"].ToString(), dt.Rows[i]["V_IDCardInfo"].ToString());
// dtData.Rows.Add(dt.Rows[i]["V_TransactionNumber"].ToString(), dt.Rows[i]["D_ShowDate"].ToString(), dt.Rows[i]["V_ShowTime"].ToString(), dt.Rows[i]["V_MovieName"].ToString(), dt.Rows[i]["N_TotalTickets"].ToString(), dt.Rows[i]["F_TotalPrice"].ToString(), strSeatNo);
if (i > 0)
{
if (dt.Rows[i - 1]["V_TransactionNumber"].ToString() == dt.Rows[i]["V_TransactionNumber"].ToString())
{
int iCount = dtData.Rows.Count - 1;
dtData.Rows[iCount - 1].Delete();
}
}
dtData.AcceptChanges();
}

grdReport.Visible = true;
lblMessage.Visible = false;
Session["DataSet"] = dtData;
grdReport.DataSource = dtData;
grdReport.DataBind();