public void DownloadExcel(int invoiceId)
{
var dbInvoice = invoiceService.GetInvoice(invoiceId);
var dbClient = clientService.GetClient(dbInvoice.ClientId);
var dbCharges = chargeService.GetInvoiceCharges(invoiceId).ToList();
var calculationResult = chargeService.CalculateCharge(invoiceId);
var unitsPerChargeName = chargeService.GetUnits(dbCharges);
var ratePerChargeName = chargeService.GetRates(dbCharges);
ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
ExcelPackage Ep = new ExcelPackage();
ExcelWorksheet Sheet = Ep.Workbook.Worksheets.Add("Invoice Print");
// Sheet labels
Sheet.Cells["B6"].Value = "Contract";
Sheet.Cells["B4"].Value = "Invoice number";
Sheet.Cells["G2"].Value = "Invoice date";
Sheet.Cells["B2"].Value = "Company name";
Sheet.Cells["G4"].Value = "Start date";
Sheet.Cells["G6"].Value = "End date";
// Sheet values
Sheet.Cells["D6"].Value = dbClient.Contract;
Sheet.Cells["D4"].Value = dbInvoice.InvoiceNumber;
Sheet.Cells["I2"].Value = string.Format("{0:d.M.yyyy}", dbInvoice.InvoiceDate);
Sheet.Cells["D2"].Value = dbInvoice.CompanyName;
Sheet.Cells["I4"].Value = string.Format("{0:d.M.yyyy}", dbInvoice.StartDate);
Sheet.Cells["I6"].Value = string.Format("{0:d.M.yyyy}", dbInvoice.EndDate);
// Sheet labels
Sheet.Cells["A10"].Value = "Charge";
Sheet.Cells["A11"].Value = "Day";
Sheet.Cells["A12"].Value = "Night";
Sheet.Cells["A13"].Value = "Weekend";
Sheet.Cells["C10"].Value = "Units";
Sheet.Cells["E10"].Value = "Rate";
Sheet.Cells["I10"].Value = "Amount";
// Sheet values
Sheet.Cells["C11"].Value = unitsPerChargeName["Day"]; // Units per day
Sheet.Cells["C12"].Value = unitsPerChargeName["Night"]; // Units per night
Sheet.Cells["C13"].Value = unitsPerChargeName["Weekend"]; // Units per weekend
Sheet.Cells["E11"].Value = ratePerChargeName["Day"];; // Rate per day
Sheet.Cells["E12"].Value = ratePerChargeName["Night"];; // Rate per night
Sheet.Cells["E13"].Value = ratePerChargeName["Weekend"];; // Rate per weekend
Sheet.Cells["I11"].Value = unitsPerChargeName["Day"] * ratePerChargeName["Day"];
Sheet.Cells["I12"].Value = unitsPerChargeName["Night"] * ratePerChargeName["Night"];
Sheet.Cells["I13"].Value = unitsPerChargeName["Weekend"] * ratePerChargeName["Weekend"];
// Sheet labels
Sheet.Cells["A16"].Value = "Total";
Sheet.Cells["A17"].Value = "Tax";
Sheet.Cells["A18"].Value = "Grand Total";
// Sheet values
Sheet.Cells["I16"].Value = calculationResult["Total"];
Sheet.Cells["I17"].Value = calculationResult["Tax"];
Sheet.Cells["I18"].Value = calculationResult["GrandTotal"];
// Execute
Sheet.Cells["A:AZ"].AutoFitColumns();
Response.Clear();
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment: filename=" + "Report.xlsx");
Response.BinaryWrite(Ep.GetAsByteArray());
Response.End();
}