RecyclerView dosent顯示以下是我的代碼

Question

Fragment_bookmovie2.java

public class Fragment_bookmovie2 extends android.support.v4.app.Fragment implements View.OnClickListener { 
private static final String TAG ="Fragment_bookmovie2" ; 
ArrayList<String> moviename= new ArrayList<>(); 
ArrayList<String> movieyear= new ArrayList<>(); 
ArrayList<String> moviebanner= new ArrayList<>(); 

private RecyclerView.LayoutManager layoutManager; 
private static RecyclerView recyclerView; 
Movie_listAdapter2 adapter ; 


LinearLayout progress; 
RelativeLayout ll; 
public Fragment_bookmovie2() { 
    // Required empty public constructor 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    //Log.e(TAG,"reched on create"); 
    // first step - retrieve object 
    Backendless.Persistence.of(Booking.class).find(new AsyncCallback<BackendlessCollection<Booking>>() { 
     @Override 
     public void handleResponse(BackendlessCollection<Booking> response) { 
      for(Booking booking : response.getData()) { 
       if(!moviename.contains(booking.getMovie().get(0).getMovie_Name())) { 
        moviename.add(booking.getMovie().get(0).getMovie_Name()); 
        movieyear.add(booking.getMovie().get(0).getYear()); 
        moviebanner.add("https://api.backendless.com/" + BackendSetting.APPLICATION_ID + "/" + BackendSetting.VERSION + "/files/mypics/" + booking.getMovie().get(0).getImage()); 
       } 
      } 
      adapter.notifyDataSetChanged(); 
      ll.removeView(progress); 
     } 

     @Override 
     public void handleFault(BackendlessFault fault) { 
      Toast.makeText(getActivity(), fault.getMessage(), Toast.LENGTH_SHORT).show(); 
     } 
    }); 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    moviename.add("haha"); 
    movieyear.add("hello"); 
    moviebanner.add("http://www.w3schools.com/css/trolltunga.jpg"); 

    // Inflate the layout for this fragment 
    ll = (RelativeLayout) inflater.inflate(R.layout.fragment_bookmovie2, container, false); 
    progress = (LinearLayout) ll.findViewById(R.id.progress_bookingFrag); 


    recyclerView = (RecyclerView) ll.findViewById(R.id.recycle_movielist); 
    recyclerView.setHasFixedSize(true); 
    layoutManager = new LinearLayoutManager(getActivity()); 
    recyclerView.setLayoutManager(layoutManager); 
    recyclerView.setItemAnimator(new DefaultItemAnimator()); 

    adapter = new Movie_listAdapter2(getActivity(),moviename,movieyear,moviebanner); 
    recyclerView.setAdapter(adapter); 
    adapter.notifyDataSetChanged(); 

    return ll; 
} 

@Override 
public void onClick(View view) { 

} 

@Override 
public void onPause() { 
    super.onPause(); 
} 

@Override 
public void onResume() { 
    super.onResume(); 
} 

/*@Override 
public void onButtonClickListnerProceed(Integer pos) { 
    Intent booking_screen_redirect = new Intent(getActivity(), BookingScreen2.class); 
    booking_screen_redirect.putExtra("movie_name",moviename.get(pos)); 
    this.onPause(); 
    startActivity(booking_screen_redirect); 
    getActivity().overridePendingTransition(R.anim.pull_in_right, R.anim.push_out_left); 

}*/ 

}

Movie_listAdapter2.java

public class Movie_listAdapter2 extends RecyclerView.Adapter<Movie_listAdapter2.Movie_cards>{ 

final static String TAG="Movie_listAdapter2"; 
Context context_external; 
ArrayList<String> moviename=new ArrayList<>(); 
ArrayList<String> movieyear=new ArrayList<>(); 
ArrayList<String> banner=new ArrayList<>(); 
public Movie_listAdapter2(Context context,ArrayList<String> resource, ArrayList<String> resource1, ArrayList<String> resource2) { 
    //set the context and the format of the layout inside the list item 
    //i.e R.layout.movie_list_adapter 
    //also the resource i.e the item names in an ArrayList 
    this.moviename = resource; 
    this.movieyear = resource1; 
    this.banner = resource2; 
    this.context_external=context; 
    Log.e(TAG,"size = "+movieyear.size()+" "+moviename.size()); 


} 
public static class Movie_cards extends RecyclerView.ViewHolder { 

    CardView cv; 
    TextView movie_name; 
    TextView movie_year; 
    Button proceed; 
    ImageView movie_banner; 

    public Movie_cards(View itemView) { 
     super(itemView); 
     cv = (CardView)itemView.findViewById(R.id.movie_list_card); 
     movie_name = (TextView)itemView.findViewById(R.id.tv_card_moviename); 
     movie_year = (TextView)itemView.findViewById(R.id.tv_card_movieyear); 
     movie_banner = (ImageView)itemView.findViewById(R.id.card_moviebanner); 
     proceed = (Button) itemView.findViewById(R.id.b_card_proceed); 
    } 
} 
@Override 
public Movie_cards onCreateViewHolder(ViewGroup parent, int viewType) { 
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_list_card, parent, false); 
    Movie_cards pvh = new Movie_cards(v); 
    return pvh; 
} 

public void updateData(ArrayList<String> resource, ArrayList<String> resource1, ArrayList<String> resource2) { 
    this.moviename = resource; 
    this.movieyear = resource1; 
    this.banner = resource2; 
    notifyDataSetChanged(); 
} 

@Override 
public void onBindViewHolder(final Movie_cards holder, final int position) { 
    holder.movie_name.setText(moviename.get(position)); 
    holder.movie_year.setText(movieyear.get(position)); 
    Picasso.with(context_external) 
      .load(banner.get(position)) 
      .placeholder(R.drawable.placeholder) 
      .networkPolicy(NetworkPolicy.OFFLINE) 
      .error(R.drawable.placeholder) 
      .fit() 
      .into(holder.movie_banner, new Callback() { 
       @Override 
       public void onSuccess() { 
        //i.e image was loaded from cache 
       } 

       @Override 
       public void onError() { 
        //image was downloaded as it wasn't available in cache 
        Picasso.with(context_external) 
          .load(banner.get(position)) 
          .placeholder(R.drawable.placeholder) 
          .error(R.drawable.warning) 
          .fit() 
          .into(holder.movie_banner); 
       } 
      }); 
    holder.proceed.setOnClickListener(new View.OnClickListener(){ 
     @Override 
     public void onClick(View v) { 
      Intent booking_screen_redirect = new Intent(context_external, BookingScreen2.class); 
      booking_screen_redirect.putExtra("movie_name",moviename.get(position)); 
      context_external.startActivity(booking_screen_redirect); 
      //overridePendingTransition(R.anim.pull_in_right, R.anim.push_out_left); 

     } 
    }); 
} 



@Override 
public int getItemCount() { 
    return 0; 
} 
@Override 
public void onAttachedToRecyclerView(RecyclerView recyclerView) { 
    super.onAttachedToRecyclerView(recyclerView); 
} 



} 

片段顯示空的並且沒有項目出現的任何元件即使我已將數據添加到arraylist和pas sed到適配器。請幫忙 。在此先感謝

Answer 1

問題在下面你要返回0代碼，這就是爲什麼它沒有顯示任何項目

@Override 
    public int getItemCount() { 
    return 0; 
} 

你應該回到這裏列表的大小或者moviename.size（）;或movieyear.size（）