// GET: 客戶資料
        public ActionResult Index(string sortOrder)
        {
            var custName = customerRepo.GetCustomerName();

            ViewBag.custName = new SelectList(custName);
            var data = customerRepo.All();

            ViewBag.custNameSortParm = String.IsNullOrEmpty(sortOrder) ? "custName_desc" : "";
            ViewBag.unNumSortParm    = String.IsNullOrEmpty(sortOrder) ? "unNum_desc" : "";
            ViewBag.telNumSortParm   = String.IsNullOrEmpty(sortOrder) ? "telNum_desc" : "";
            ViewBag.faxNumSortParm   = String.IsNullOrEmpty(sortOrder) ? "faxNum_desc" : "";
            ViewBag.addressSortParm  = String.IsNullOrEmpty(sortOrder) ? "address_desc" : "";
            ViewBag.emailSortParm    = String.IsNullOrEmpty(sortOrder) ? "email_desc" : "";

            switch (sortOrder)
            {
            case "custName_desc":
                data = data.OrderByDescending(o => o.客戶名稱);
                break;

            case "unNum_desc":
                data = data.OrderByDescending(o => o.統一編號);
                break;

            case "telNum_desc":
                data = data.OrderByDescending(o => o.電話);
                break;

            case "faxNum_desc":
                data = data.OrderByDescending(o => o.傳真);
                break;

            case "address_desc":
                data = data.OrderByDescending(o => o.地址);
                break;

            case "email_desc":
                data = data.OrderByDescending(o => o.Email);
                break;

            default:
                data = data.OrderBy(o => o.Id);
                break;
            }



            return(View(data.ToList()));
        }