notifyDataSetChanged auf RecyclerView android

Question

Ich habe ein Problem mit meinem Code in notifyDataSetChanged auf Recyclerview. Hier ist mein Code, bitte helfen Sie mir, es zu beheben.

public class FragmentListFilm extends BaseFragment { 

    private static final String TAG = FragmentListFilm.class.getSimpleName(); 
    private static final String url "http://api.androidhive.info/json/movies.json"; 
    private List<InforFilm> inforFilms = new ArrayList<InforFilm>(); 
    private Fragment_Film_Adapter adapter; 
    private DialogActivity dialogActivity; 
    View root; 
    private ProgressDialog pDialog; 
    private RecyclerView rv; 

    @Override 
    public void onCreate(@Nullable Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 

    } 
    @Nullable 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     root = inflater.inflate(R.layout.fragment_film, container, false); 
     rv = (RecyclerView) root.findViewById(R.id._recycler_fragment_film); 
     setUpRecycleView(rv); 

     return root; 
    } 

    private void setUpRecycleView(RecyclerView recycleView) { 
     recycleView.setLayoutManager(new LinearLayoutManager(recycleView.getContext())); 
     recycleView.setAdapter(adapter); 

     pDialog = new ProgressDialog(getActivity()); 
     // Showing progress dialog before making http request 
     pDialog.setMessage("Loading..."); 
     pDialog.show(); 

     // recycleView. 
     JsonArrayRequest movieReq = new JsonArrayRequest(url, 
       new Response.Listener<JSONArray>() { 
        @Override 
        public void onResponse(JSONArray response) { 
         Log.d(TAG, response.toString()); 
         hidePDialog(); 

         // Parsing json 
         for (int i = 0; i < response.length(); i++) { 
          try { 
           // Log.d(TAG, "try-cat"); 
           JSONObject obj = response.getJSONObject(i); 
           InforFilm film = new InforFilm(); 

           film.setTitle(obj.getString("title")); 
           film.setThumbail(obj.getString("image")); 
           film.setRating(((Number) obj.get("rating")) 
             .doubleValue()); 
           film.setYear(obj.getInt("releaseYear")); 

           // Genre is json array 
           JSONArray genreArry = obj.getJSONArray("genre"); 
           ArrayList<String> genre = new ArrayList<String>(); 
           for (int j = 0; j < genreArry.length(); j++) { 
            genre.add((String) genreArry.get(j)); 
           } 
           film.setGender(genre); 

           // adding movie to movies array 
           inforFilms.add(film); 


          } catch (JSONException e) { 
           e.printStackTrace(); 
          } 
         } 

         // notifying list adapter about data changes 
         // so that it renders the list view with updated data 
         Log.d(TAG, "notifydatasetchanged"); 
         adapter.notifyDataSetChanged(); 

        } 
       }, new Response.ErrorListener() { 
      @Override 
      public void onErrorResponse(VolleyError error) { 
       VolleyLog.d(TAG, "Error: " + error.getMessage()); 
       hidePDialog(); 

      } 
     }); 

     // Adding request to request queue 
     AppController.getInstance().addToRequestQueue(movieReq); 
    } 

    private void hidePDialog() { 
     if (pDialog != null) { 
      pDialog.dismiss(); 
      pDialog = null; 
     } 
    } 

} 

////// Adapter

public class Fragment_Film_Adapter extends RecyclerView.Adapter<Fragment_Film_Adapter.ViewHolder> { 

    private List<InforFilm> inforFilms; 
    ImageLoader imageLoader = AppController.getInstance().getmImageLoader(); 

    public Fragment_Film_Adapter(List<InforFilm> inforFilms) { 
     this.inforFilms = inforFilms; 
    } 

    public class ViewHolder extends RecyclerView.ViewHolder { 

     @Bind(R.id.film_thumbnail) 
     NetworkImageView thumbNail; 
     @Bind(R.id.film_genre) 
     TextView gender; 
     @Bind(R.id.film_rating) 
     TextView rating; 
     @Bind(R.id.film_title) 
     TextView title; 
     @Bind(R.id.film_releaseYear) 
     TextView year; 

     public ViewHolder(View view) { 
      super(view); 
     } 
    } 

    @Override 
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 

     View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_film_item, parent, false); 

     return new ViewHolder(view); 
    } 

    @Override 
    public void onBindViewHolder(ViewHolder holder, int position) { 
     InforFilm infor = inforFilms.get(position); 

     holder.thumbNail.setImageUrl(infor.getThumbail(), imageLoader); 
     holder.title.setText(infor.getTitle()); 
     holder.rating.setText(String.valueOf(infor.getRating())); 
     holder.year.setText(infor.getYear()); 
     String genreStr = ""; 
     for (String str : infor.getGender()) { 
      genreStr += str + ", "; 
     } 
     genreStr = genreStr.length() > 0 ? genreStr.substring(0, 
       genreStr.length() - 2) : genreStr; 
     holder.gender.setText(genreStr); 
    } 

    @Override 
    public int getItemCount() { 
     return inforFilms.size(); 
    } 


} 

Es wirft die folgende Ausnahme:

Attempt to invoke virtual method 'void com.example.qtv.qtvmaterial.adapter.Fragment_Film_Adapter.notifyDataSetChanged()' on a null object reference 
     at com.example.qtv.qtvmaterial.fragment.FragmentListFilm$1.onResponse(FragmentListFilm.java:110) 
     at com.example.qtv.qtvmaterial.fragment.FragmentListFilm$1.onResponse(FragmentListFilm.java:71) 

Answer 1

Bevor Adapter RecyclerView Einstellung initialisieren:

recycleView.setLayoutManager(new LinearLayoutManager(recycleView.getContext())); 
adapter = new Fragment_Film_Adapter(inforFilms); 
recycleView.setAdapter(adapter);