public async Task <IActionResult> CountByCustomerMonth(CountByCustomerMonthViewModel model)
        {
            if (ModelState.IsValid)
            {
                model.Customers = await GetCustomerCountsByMonthAsync(model.Nam, model.Thang);

                ViewBag.Months = new SelectList(model.Months, "ID", "Ten", model.Thang);
                ViewBag.Years  = new SelectList(model.Years, model.Nam);
            }
            return(View(model));
        }
        public async Task <IActionResult> CountByCustomerMonth()
        {
            var nowm  = DateTime.Today.Month;
            var nowy  = DateTime.Today.Year;
            var model = new CountByCustomerMonthViewModel
            {
                Thang     = nowm,
                Nam       = nowy,
                Customers = await GetCustomerCountsByMonthAsync(nowy, nowm)
            };

            ViewBag.Months = new SelectList(model.Months, "ID", "Ten", nowm);
            ViewBag.Years  = new SelectList(model.Years, nowy);
            return(View(model));
        }