public async Task <IActionResult> OnPostAsync() { var tracks = await _apiClient.GetTracksAsync(); if (tracks.Any(t => t.Name == Track.Name && t.ConferenceID == Track.ConferenceID)) { ModelState.AddModelError("Track.Name", $"The track name {Track.Name} exists already"); } if (!ModelState.IsValid) { await GetConferences(); return(Page()); } Message = "Track created successfully!"; await _apiClient.AddTrackAsync(Track); return(RedirectToPage()); }