System.Data.DataTable.Load C# (CSharp) Method

        public virtual void Load(IDataReader reader, LoadOption loadOption, FillErrorEventHandler errorHandler)
        {
            long logScopeId = DataCommonEventSource.Log.EnterScope("<ds.DataTable.Load|API> {0}, loadOption={1}", ObjectID, loadOption);
            try
            {
                if (PrimaryKey.Length == 0)
                {
                    DataTableReader dtReader = reader as DataTableReader;
                    if (dtReader != null && dtReader.CurrentDataTable == this)
                    {
                        return; // if not return, it will go to infinite loop
                    }
                }
                Common.LoadAdapter adapter = new Common.LoadAdapter();
                adapter.FillLoadOption = loadOption;
                adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
                if (null != errorHandler)
                {
                    adapter.FillError += errorHandler;
                }
                adapter.FillFromReader(new DataTable[] { this }, reader, 0, 0);

                if (!reader.IsClosed && !reader.NextResult())
                {
                    reader.Close();
                }
            }
            finally
            {
                DataCommonEventSource.Log.ExitScope(logScopeId);
            }
        }

        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();
        }