retrieve hidden data from gridview

[prajin]

i have to retrieve hidden data from gridview.
hidden data is Usr_No. then i need to update the record based on that condition. now i am getting the hidden data. but only first record is updating.when i am trying to update next records error message is showing like Object reference not set to an instance of an object.


my code is

protected void grdCandidate_Update(object sender, GridViewUpdateEventArgs e)
{
try
{

SqlConnection con = new SqlConnection(connStr);
con.Open();
foreach (GridViewRow row in grdCandidate.Rows)
{
int index = e.RowIndex;
int pageindex = grdCandidate.PageIndex;
int pagecount = grdCandidate.PageSize;
int selectedindex = (pageindex) * (pagecount) + index;
DataSet ds2 = (DataSet)ViewState["Data"];
string usr_sno = ds2.Tables[0].Rows[selectedindex]["usr_sno"].ToString();
//string Round_Desg = ((DropDownList)row.FindControl("ddlStatus")).Selec tedItem.Value;
string Round_Desg = ((DropDownList)row.FindControl("ddlStatus")).Selec tedItem.Value;
Response.Write(Round_Desg);

string sqlUpdate = "update TB_NISI_Interviewdetails set Round_Desg=@Round_Desg where usr_sno=@usr_sno";
SqlCommand cmd = new SqlCommand(sqlUpdate, con);
//cmd.Parameters.AddWithValue("@Company_Name", ddlCompanyName.SelectedItem.Text);
//cmd.Parameters.AddWithValue("@inter_date", txtDate.Text);
cmd.Parameters.AddWithValue("@Round_Desg", Round_Desg);
cmd.Parameters.AddWithValue("@usr_sno", usr_sno);
cmd.ExecuteNonQuery();
con.Close();
BindData();
}
}
catch (Exception ex)
{
string a = ex.ToString();
}
}

plz help me.

[kenobewan]

Welcome to TSDN. I cant find "hidden data is Usr_No", do you mean usr_sno?