public ActionResult AddBookDetail() { Book addingBook = (Book)TempData["addingBook"]; List <TopicViewModel> topics = UIHelper.GetTopicTree();;// = UIHelper.GetTopicTree(); ViewBag.TopicList = topics; ViewBag.FileName = addingBook.Name; TempData["AddingBook"] = addingBook; return(View(ModelConverter.BookToView(addingBook))); }