Hi,
i am facing this exception on this line.
int d = (int)dr["TTW"];
when my ExecuteReader is null
here is my c# code
protected void DDLContno_SelectedIndexChanged(object sender, EventArgs e)
{
String strQuery = "select ConWeight from Containerno where CID=@CID";
SqlConnection con = new SqlConnection();
SqlCommand cmde = new SqlCommand();
cmde.Parameters.AddWithValue("@CID", DDLContno.SelectedValue);
cmde.CommandType = CommandType.Text;
cmde.CommandText = strQuery;
cmde.Connection = con;
try
{
con.Open();
SqlDataReader sdr = cmde.ExecuteReader();
while (sdr.Read())
{
txtTweght.Text = sdr[0].ToString();
}
}
catch (Exception ex)
{
throw ex;
}
finally
{
}
if
(txtctweight.Text != "")
{
String S2 = "Select Sum(IWeight) as TTW from ConIssuance where CID='" + DDLContno.SelectedValue + "'";
SqlCommand cmd = new SqlCommand(S2, con);
SqlDataReader dr;
dr = cmd.ExecuteReader();
if (dr.Read())
{
int? d = (int?)dr["TTW"];
TBSTDID.Visible = true;
txtctweight.Text = Convert.ToString(d);
}
{
int a = Convert.ToInt32(txtTweght.Text);
int b = Convert.ToInt32(txtctweight.Text);
int d = a - b;
TextBox1.Text = Convert.ToString(d);
con.Close();
con.Dispose();
}
}
}
please guide
