private void button1_Click(object sender, EventArgs e) { int item = comboBox1.SelectedIndex; OrderBasket order = new OrderBasket(); switch (item) { case 1: GetOrderItems(order); break; case 2: GetOrderBasket2Items(order); break; case 3: GetOrderBasket3Items(order); break; default: break; } OrderReciept response = m_TaxCalculator.TaxCalculation(order); DataTable dtResult = new DataTable(); dtResult.Columns.Add("Item", typeof(string)); dtResult.Columns.Add("Item qty", typeof(string)); dtResult.Columns.Add("Item price", typeof(string)); if (response.IsTaxCalculationDone) { DataRow row; foreach (TaxRequestItem taxitem in response.TaxRequestItems) { row = dtResult.NewRow(); row["Item"] = taxitem.Item; row["Item qty"] = taxitem.ItemQuantity; row["Item price"] = taxitem.Price; dtResult.Rows.Add(row); } row = dtResult.NewRow(); row["Item qty"] = "sales tax"; row["Item price"] = response.SalesTax; dtResult.Rows.Add(row); row = dtResult.NewRow(); row["Item qty"] = "Total Price"; row["Item price"] = response.TotalPrice; dtResult.Rows.Add(row); } dataGridView1.DataSource = dtResult; }