public IActionResult OnPost() { if (!ModelState.IsValid) { CityType = htmlHelper.GetEnumSelectList <CityType>(); return(Page()); } if (City.Id > 0) { cityData.Update(City); } else { cityData.Add(City); } cityData.Commit(); TempData["Message"] = "City saved!"; return(RedirectToPage("./Detail", new { cityId = City.Id })); }