public ActionResult Index() { var data = _forum.GetCategoryData(); PostData new_forum = new PostData { CList = new List <PCategoryData>() }; foreach (var d in data) { var topic = new List <PTopicData>(); var cat = new PCategoryData() { CategoryID = d.CategoryID, Title = d.Title, Topics = new List <PTopicData>() }; foreach (var t in d.Topics) { var local = new PTopicData() { TopicID = t.TopicID, Title = t.Title }; topic.Add(local); } cat.Topics = topic; new_forum.CList.Add(cat); } return(View(new_forum)); }