public  ActionResult DownloadXLS(String Provincia, String Stato)
        {         
            //filtro modello
            var model = db.ANAGRAFICA.AsNoTracking().AsQueryable();

            if (!string.IsNullOrEmpty(Provincia)) { 
                model = model.Where(item => item.Prov == Provincia);
            }
            if (!string.IsNullOrEmpty(Stato)) { 
                model = model.Where(item => item.Stato == Stato);
            }
            try
            {
                var workbook = new HSSFWorkbook();

                var sheet = workbook.CreateSheet();

                var headerRow = sheet.CreateRow(0);

                headerRow.CreateCell(0).SetCellValue("RagSociale");
                headerRow.CreateCell(1).SetCellValue("Indirizzo");
                headerRow.CreateCell(2).SetCellValue("Comume");
                headerRow.CreateCell(3).SetCellValue("Cap");
                headerRow.CreateCell(4).SetCellValue("Provincia");

                //(Optional) freeze the header row so it is not scrolled
                sheet.CreateFreezePane(0, 1, 0, 1);

                int rowNumber = 1;

                //Populate the sheet with values from the grid data
                foreach (ANAGRAFICA a in model)
                {
                    //Create a new row
                    var row = sheet.CreateRow(rowNumber++);

                    //Set values for the cells
                    row.CreateCell(0).SetCellValue(a.RagSoc);
                    row.CreateCell(1).SetCellValue(a.Indiri);
                    row.CreateCell(2).SetCellValue(a.Comune);
                    row.CreateCell(3).SetCellValue(a.Cap);
                    row.CreateCell(4).SetCellValue(a.Prov);

                }

                MemoryStream output = new MemoryStream();
                workbook.Write(output);

                return File(output.ToArray(), "application/vnd.ms-excel", "Anagrafica.xls"); 
               
            }

            catch (Exception ex)
            {
                TempData["Message"] = "Oops! Some error occurs.";

                return RedirectToAction("Index");
            }

            
        }

@Html.ActionLink("XLS", "DownloadXLS", new { Provincia = Request["Provincia"], Stato = Request["Stato"] }, new { id = "exportLink" , @class="btn btn-success"})