CSPosAPI.MainForm.dataGridViewStocks_CellValueChanged C# (CSharp) Метод

        private void dataGridViewStocks_CellValueChanged(object sender, DataGridViewCellEventArgs e)
        {
            summaryAmount = 0;
            summaryVat = 0;
            summaryCityTax = 0;
            foreach (DataGridViewRow row in dataGridViewStocks.Rows)
            {
                if (!row.IsNewRow)
                {
                    double qty = Convert.ToDouble(row.Cells["Qty"].Value);
                    double unitPrice = Convert.ToDouble(row.Cells["UnitPrice"].Value);
                    double vat = Convert.ToDouble(row.Cells["Vat"].Value);
                    double cityTax = Convert.ToDouble(row.Cells["CityTax"].Value);
                    double unitPriceNonVat = Convert.ToDouble(row.Cells["UnitPriceNonVat"].Value);
                   // double summary = qty * (unitPrice + cityTax);
                    double summary = qty * (unitPrice);
                   // row.Cells["UnitPrice"].Value = (unitPriceNonVat * 1.1).ToString(Program.NUMBER_FORMAT);
                    //row.Cells["Vat"].Value = (unitPriceNonVat * 0.1).ToString(Program.NUMBER_FORMAT);
                    row.Cells["UnitPrice"].Value = (unitPriceNonVat * 1).ToString(Program.NUMBER_FORMAT);
                   // row.Cells["Vat"].Value = (unitPriceNonVat * 1).ToString(Program.NUMBER_FORMAT);
                    row.Cells["Amount"].Value = summary.ToString(Program.NUMBER_FORMAT);
                    summaryAmount += summary;
                    summaryVat += vat;
                    summaryCityTax += cityTax;
                }
            }
        }