System.Data.OleDb.OleDbCommand.ExecuteReader C# (CSharp) Method

		public new OleDbDataReader ExecuteReader()
		{
			return (OleDbDataReader)ExecuteReader(CommandBehavior.Default);
		}

        private void lc(object sender, MouseEventArgs e)
        {
            c.Open();
            DataSet ds = new DataSet();
            string query = "select ID,pname,bill,pbill from pdetails where date=@bc ";
            OleDbCommand cmd = new OleDbCommand(query, c);
            cmd.Parameters.Add("@bc", OleDbType.Date).Value = dateTimePicker1.Value.Date;
            OleDbDataReader dr = cmd.ExecuteReader();
            DataTable dt = new DataTable();
            dt.Load(dr);
            /*ds.Tables.Add(dt);
            OleDbDataAdapter da = new OleDbDataAdapter();
            da.Fill(dt);*/
            dataGridView1.DataSource = dt.DefaultView;
            c.Close();
            try
            {
                c.Open();
                String str = @"SELECT SUM(pbill) FROM pdetails WHERE date=@bb;";

                OleDbCommand comm2 = new OleDbCommand(str, c);
                comm2.Parameters.Add("@bb", OleDbType.Date).Value = dateTimePicker1.Value.Date;
                bill = Convert.ToDouble(comm2.ExecuteScalar());

                label3.Text = bill.ToString() + "/-";
            }
            catch(Exception ex)
            {
                MessageBox.Show("selected date miss match");
                c.Close();
            }
                c.Close();
        }