Updating the Controller

Go back to our Controller class.

1. Call the ComicBookRepository class.

   private ComicBookRepository _comicBookRepository = null;
   

2. Create a constructor for ComicBooksController class.

   public ComicBooksController()
   {
       _comicBookRepository = new ComicBookRepository();
   }
   

3. Change our ActionResult to be like this.

   public ActionResult Detail(int id)
   {
       var comicBook = _comicBookRepository.GetComicBook(id);
   
       return View(comicBook);
   }
   

4. Take a look at our controller, it doesn't show anything because we already replaced the view.

5. Got an error, huh?
6. URL Routing pattern that we know -> controller/action. The actual pattern is controller/action/id.
7. Actually, MVC stills recognize both of the pattern, but it confusing. Unfortunately, our Detail method needs an input that not nullable. To make the method receive a nullable input, try change to this.

   public ActionResult Detail(int? id)
   

8. Now, let's code some conditional operation if the id is null.

   public ActionResult Detail(int? id)
   {
       if (id == null)
           return HttpNotFound();
   
       var comicBook = _comicBookRepository.GetComicBook((int) id);
   
       return View(comicBook);
   }