public async Task <IActionResult> Create([Bind("IdRegion,Name")] Region region, string[] selectedTrails) { if (selectedTrails != null) { region.RegionLocation = new List <RegionLocation>(); foreach (var trail in selectedTrails) { var trailToAdd = new RegionLocation { IdRegion = region.IdRegion, IdTrail = int.Parse(trail) }; region.RegionLocation.Add(trailToAdd); } } if (ModelState.IsValid) { await _regionRepository.AddRegionAsync(region); return(RedirectToAction(nameof(Index))); } PopulateRegion(region); return(View(region)); }