how to add columns having templatefield dynamically in gridview in asp.net

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System;

System.Configuration;

System.Data;

System.Data.SqlClient;

System.Linq;

System.Web;

System.Web.Security;

System.Web.UI;

System.Web.UI.HtmlControls;

System.Web.UI.WebControls;

System.Web.UI.WebControls.WebParts;

System.Xml.Linq;

partial class _Default : System.Web.UI.Page

SqlDataAdapter dadapter;

DataSet dset;

string connstring = "Data Source=SMART-PC;Initial Catalog=MyNorthwind;Integrated Security=True";

string sql = "select * from Class";

protected void Page_Load(object sender, EventArgs e)

if (!IsPostBack)

new SqlDataAdapter(sql, connstring);

new DataSet();

"ClassName";

"ClassId";

SqlConnection con = new SqlConnection("Data Source=SMART-PC;Initial Catalog=MyNorthwind;Integrated Security=True");

SqlDataAdapter da = new SqlDataAdapter("select Starttime,Endtime  from TimeTableMain where ClassId='" + DropDownList1.SelectedValue + "'", con);

DataTable dt = new DataTable();

DataRow dr = dt.NewRow();       

false;

public static DataTable FlipDataTable(DataTable dt)

DataTable table = new DataTable();

//Get all the rows and change into columns

for (int i = 0; i <= dt.Rows.Count; i++)

Convert.ToString(i));

DataRow dr;

//get all the columns and make it as rows

for (int j = 0; j < dt.Columns.Count; j++)

for (int k = 1; k <= dt.Rows.Count; k++)

return table;