Continuous défilement dans recyclerview par demande Json et ajout d'un nouvel élément avec

Question

Je veux implémenter le défilement sans fin dans recyclerview en appelant la nouvelle demande JSON avec l'augmentation du nombre de page et en ajoutant ce résultat avec les résultats précédents. première demande montre 20 résultats, mais il y a plus de 200 résultats laissés à show.How je peux avoir défilement sans fin avec fonction onLoadMore() dans « aide TopratedFragment.java'.Please avec les codes

de TopratedFragment.java

import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 

import com.android.volley.Request; 
import com.android.volley.RequestQueue; 
import com.android.volley.Response; 
import com.android.volley.VolleyError; 
import com.android.volley.toolbox.ImageLoader; 
import com.android.volley.toolbox.JsonObjectRequest; 
import com.example.mitab.mentor.Movies.Pages.L; 
import com.example.mitab.mentor.Movies.Pages.MyApplication; 
import com.example.mitab.mentor.Movies.Pages.VolleySingleton; 
import com.example.mitab.mentor.Movies.Pages.movie; 
import com.example.mitab.mentor.R; 

import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import java.text.ParseException; 
import java.text.SimpleDateFormat; 
import java.util.ArrayList; 
import java.util.Date; 
import android.os.Handler; 

import static com.example.mitab.mentor.Movies.Pages.Keys.EndpointToprated.*; 

/** 
* A simple {@link Fragment} subclass. 
* Use the {@link TopratedFragment#newInstance} factory method to 
* create an instance of this fragment. 
*/ 
public class TopratedFragment extends Fragment { 
    // TODO: Rename parameter arguments, choose names that match 
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER 
    private static final String ARG_PARAM1 = "param1"; 
    private static final String ARG_PARAM2 = "param2"; 
    public static final String Top_rated="http://api.themoviedb.org/3/movie/top_rated"; 

    // TODO: Rename and change types of parameters 
    private String mParam1; 
    private String mParam2; 
    protected Handler handler; 
    private VolleySingleton volleySingleton; 
    private ImageLoader imageLoader; 
    int page=1; 
    private RequestQueue requestQueue; 
    private ArrayList<movie> listMovies=new ArrayList<>(); 
    private ArrayList<movie> newlistMovies=new ArrayList<>(); 
    private SimpleDateFormat dateFormat=new SimpleDateFormat("yyyy-MM-dd"); 
    private RecyclerView listMovieHits; 
    private AdapterToprated adapterToprated; 
    boolean loadingMore = false; 
    private int lastVisibleItemId=0; 


    public TopratedFragment() { 
     // Required empty public constructor 
    } 

    // TODO: Rename and change types and number of parameters 
    public static TopratedFragment newInstance(String param1, String param2) { 
     TopratedFragment fragment = new TopratedFragment(); 
     Bundle args = new Bundle(); 
     args.putString(ARG_PARAM1, param1); 
     args.putString(ARG_PARAM2, param2); 
     fragment.setArguments(args); 
     return fragment; 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     if (getArguments() != null) { 
      mParam1 = getArguments().getString(ARG_PARAM1); 
      mParam2 = getArguments().getString(ARG_PARAM2); 
     } 

     volleySingleton= VolleySingleton.getsInstance(); 
     requestQueue=volleySingleton.getRequestQueue(); 

     sendJsonRequest(); 
    } 

    private void sendJsonRequest(){ 
     JsonObjectRequest request=new JsonObjectRequest(Request.Method.GET, getRequestUrl(page), (String)null, new Response.Listener<JSONObject>() { 
      @Override 
      public void onResponse(JSONObject response) { 
       listMovies=parseJSONResponse(response); 
       adapterToprated.setMovieList(listMovies); 
      } 
     }, new Response.ErrorListener() { 
      @Override 
      public void onErrorResponse(VolleyError error) { 

      } 
     }); 
     requestQueue.add(request); 
    } 

    private ArrayList<movie> parseJSONResponse(JSONObject response){ 
     ArrayList<movie> listMovies=new ArrayList<>(); 
     if (response==null || response.length()>0){ 



      try { 
       JSONArray arrayMovies=response.getJSONArray(KEY_MOVIES); 
       for (int i=0;i<arrayMovies.length();i++){ 

        long id=-1; 
        String title="NA"; 
        String poster="NA"; 
        String release="NA"; 
        String overview="NA"; 
        String vote="NA"; 
        String votecount="NA"; 

        JSONObject currentMovie=arrayMovies.getJSONObject(i); 

        //get the id of current movie 
        if (currentMovie.has(KEY_ID)&& !currentMovie.isNull(KEY_ID)){ 
         id=currentMovie.getLong(KEY_ID); 
        } 

        if (currentMovie.has(KEY_TITLE)&& !currentMovie.isNull(KEY_TITLE)){ 
         title=currentMovie.getString(KEY_TITLE); 
        } 

        if (currentMovie.has(KEY_POSTER_PATH)&& !currentMovie.isNull(KEY_POSTER_PATH)){ 
         poster=currentMovie.getString(KEY_POSTER_PATH); 
        } 

        if (currentMovie.has(KEY_RELEASE_DATE)&& !currentMovie.isNull(KEY_RELEASE_DATE)){ 
         release=currentMovie.getString(KEY_RELEASE_DATE); 
        } 

        if (currentMovie.has(KEY_OVERVIEW)&& !currentMovie.isNull(KEY_OVERVIEW)){ 
         overview=currentMovie.getString(KEY_OVERVIEW); 
        } 

        if (currentMovie.has(KEY_AVERAGE_VOTE)&& !currentMovie.isNull(KEY_AVERAGE_VOTE)){ 
         vote=currentMovie.getString(KEY_AVERAGE_VOTE); 
        } 

        if (currentMovie.has(KEY_VOTE_COUNT)&& !currentMovie.isNull(KEY_VOTE_COUNT)){ 
         votecount=currentMovie.getString(KEY_VOTE_COUNT); 
        } 







        JSONArray genre=currentMovie.getJSONArray(KEY_GENRE_IDS); 

        if (currentMovie.has(KEY_GENRE_IDS)&& !currentMovie.isNull(KEY_GENRE_IDS)){ 
         for (int j=0;j<genre.length();j++){ 
          try { 
           String itemInArray=genre.getString(j); 

          } 
          catch (JSONException e){ 

          } 
         } 
        } 


        movie movie=new movie(); 
        movie.setId(id); 
        movie.setTitle(title); 
        movie.setOverview(overview); 
        movie.setAveragevote(vote); 
        Date date=null; 
        try { 
         date=dateFormat.parse(release); 
        } 
        catch (ParseException e){ 

        } 

        movie.setReleasedate(date); 
        movie.setImage(poster); 
        movie.setVotecount(votecount); 

        if (id!=-1 && !title.equals("NA")) 
        { 
         listMovies.add(movie); 
        } 


       } 



      } 
      catch (JSONException e){ 

      } 
     } 
     return listMovies; 
    } 

    public static String getRequestUrl(int page){ 
     return Top_rated +"?api_key="+ MyApplication.API_KEY + "&page="+page; 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View view=inflater.inflate(R.layout.fragment_toprated, container, false); 

     final LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity()); 
     handler=new Handler(); 
     listMovieHits=(RecyclerView) view.findViewById(R.id.listMovieHits); 
     listMovieHits.setLayoutManager(linearLayoutManager); 

     adapterToprated=new AdapterToprated(getActivity()); 
     listMovieHits.setAdapter(adapterToprated); 
     //sendJsonRequest(); 
     // Add the scroll listener 
     listMovieHits.addOnScrollListener(new EndlessRecyclerViewScrollListener(linearLayoutManager) { 
      @Override 
      public void onLoadMore(int page, int totalItemsCount) { 
       loadingMore=true; 
       sendJsonRequest(); 
       int curlsize=adapterToprated.getItemCount(); 
       listMovies.addAll(newlistMovies); 
       adapterToprated.notifyItemRangeChanged(curlsize,listMovies.size()-2); 
      } 
     }); 
     // Inflate the layout for this fragment 
     return view; 
    } 



} 

AdapterToprated.java

import android.app.Fragment; 
import android.app.FragmentManager; 
import android.content.Context; 
import android.content.Intent; 
import android.os.Bundle; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AbsListView; 
import android.widget.ImageView; 
import android.widget.LinearLayout; 
import android.widget.RelativeLayout; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.android.volley.VolleyError; 
import com.android.volley.toolbox.ImageLoader; 
import com.example.mitab.mentor.MainActivity; 
import com.example.mitab.mentor.Movies.Pages.L; 
import com.example.mitab.mentor.Movies.Pages.VolleySingleton; 
import com.example.mitab.mentor.Movies.Pages.movie; 
import com.example.mitab.mentor.R; 

import java.text.SimpleDateFormat; 
import java.util.ArrayList; 
import java.util.Date; 


public class AdapterToprated extends RecyclerView.Adapter<AdapterToprated.ViewHolderToprated> { 

    private LayoutInflater layoutInflater; 
    private VolleySingleton volleySingleton; 
    private ImageLoader imageLoader; 
    private ArrayList<movie> listMovies=new ArrayList<movie>(); 
    private SimpleDateFormat dateFormat=new SimpleDateFormat("yyyy-MM-dd"); 
    private RecyclerView.OnItemTouchListener onItemTouchListener; 
    Context context; 



    public AdapterToprated(Context context){ 
     layoutInflater=LayoutInflater.from(context); 
     volleySingleton=VolleySingleton.getsInstance(); 
     imageLoader=volleySingleton.getImageLoader(); 
     this.context = context; 
    } 

    public void setMovieList(ArrayList<movie> listMovies){ 
     this.listMovies=listMovies; 
     notifyItemRangeChanged(0, listMovies.size()); 
    } 
    @Override 
    public ViewHolderToprated onCreateViewHolder(ViewGroup parent, int viewType) { 
     View view=layoutInflater.inflate(R.layout.individual_toprated, parent, false); 
     ViewHolderToprated viewHolderToprated=new ViewHolderToprated(view); 
     return viewHolderToprated; 
    } 

    @Override 
    public void onBindViewHolder(final ViewHolderToprated holder, int position) { 
     final movie currentMovie=listMovies.get(position); 
     holder.movieTitle.setText(currentMovie.getTitle()); 
     Date movieReleaseDate=currentMovie.getReleasedate(); 
     if (movieReleaseDate!=null){ 
      String formattedDate=dateFormat.format(movieReleaseDate); 
      holder.movieReleaseDate.setText(formattedDate); 
     }else{ 
      holder.movieReleaseDate.setText("NA"); 
     } 

     holder.movieRating.setText(currentMovie.getAveragevote()); 
     String urlThumnail=currentMovie.getImage(); 
     if (!urlThumnail.equals("NA")){ 
      imageLoader.get(urlThumnail, new ImageLoader.ImageListener() { 
       @Override 
       public void onResponse(ImageLoader.ImageContainer response, boolean isImmediate) { 
        holder.movieThumbnail.setImageBitmap(response.getBitmap()); 
       } 

       @Override 
       public void onErrorResponse(VolleyError error) { 

       } 
      }); 
     } 
     holder.lnrLayout.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent intent=new Intent(context,Intentpass.class); 
       Bundle extras=new Bundle(); 
       extras.putString("Title","currentMovie.getTitle()"); 
       extras.putString("Date","formattedDate"); 
       extras.putString("Rating","currentMovie.getAveragevote()"); 
       intent.putExtras(extras); 
       context.startActivity(intent); 
       //intent.putExtra("details",currentMovie.getTitle()); 
       //context.startActivity(intent); 

      } 
     }); 


    } 

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

    static class ViewHolderToprated extends RecyclerView.ViewHolder{ 

     private ImageView movieThumbnail; 
     private TextView movieTitle; 
     private TextView movieReleaseDate; 
     private TextView movieRating; 
     private RelativeLayout lnrLayout; 

     public ViewHolderToprated(View itemView) { 
      super(itemView); 
      movieThumbnail=(ImageView) itemView.findViewById(R.id.movieThumbnail); 
      movieTitle=(TextView) itemView.findViewById(R.id.movieTitle); 
      movieReleaseDate=(TextView) itemView.findViewById(R.id.movieReleaseDate); 
      movieRating=(TextView) itemView.findViewById(R.id.movieRating); 
      lnrLayout=(RelativeLayout)itemView.findViewById(R.id.lnLayout); 
     } 
    } 
} 

EndlessRecyclerViewScrollListener.java

import android.support.v7.widget.GridLayoutManager; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.support.v7.widget.StaggeredGridLayoutManager; 

public abstract class EndlessRecyclerViewScrollListener extends RecyclerView.OnScrollListener { 
    // The minimum amount of items to have below your current scroll position 
    // before loading more. 
    private int visibleThreshold = 5; 
    // The current offset index of data you have loaded 
    private int currentPage = 0; 
    // The total number of items in the dataset after the last load 
    private int previousTotalItemCount = 0; 
    // True if we are still waiting for the last set of data to load. 
    private boolean loading = true; 
    // Sets the starting page index 
    private int startingPageIndex = 0; 

    RecyclerView.LayoutManager mLayoutManager; 

    public EndlessRecyclerViewScrollListener(LinearLayoutManager layoutManager) { 
     this.mLayoutManager = layoutManager; 
    } 

    public EndlessRecyclerViewScrollListener(GridLayoutManager layoutManager) { 
     this.mLayoutManager = layoutManager; 
     visibleThreshold = visibleThreshold * layoutManager.getSpanCount(); 
    } 

    public EndlessRecyclerViewScrollListener(StaggeredGridLayoutManager layoutManager) { 
     this.mLayoutManager = layoutManager; 
     visibleThreshold = visibleThreshold * layoutManager.getSpanCount(); 
    } 

    public int getLastVisibleItem(int[] lastVisibleItemPositions) { 
     int maxSize = 0; 
     for (int i = 0; i < lastVisibleItemPositions.length; i++) { 
      if (i == 0) { 
       maxSize = lastVisibleItemPositions[i]; 
      } 
      else if (lastVisibleItemPositions[i] > maxSize) { 
       maxSize = lastVisibleItemPositions[i]; 
      } 
     } 
     return maxSize; 
    } 

    // This happens many times a second during a scroll, so be wary of the code you place here. 
    // We are given a few useful parameters to help us work out if we need to load some more data, 
    // but first we check if we are waiting for the previous load to finish. 
    @Override 
    public void onScrolled(RecyclerView view, int dx, int dy) { 
     int lastVisibleItemPosition = 0; 
     int totalItemCount = mLayoutManager.getItemCount(); 

     if (mLayoutManager instanceof StaggeredGridLayoutManager) { 
      int[] lastVisibleItemPositions = ((StaggeredGridLayoutManager) mLayoutManager).findLastVisibleItemPositions(null); 
      // get maximum element within the list 
      lastVisibleItemPosition = getLastVisibleItem(lastVisibleItemPositions); 
     } else if (mLayoutManager instanceof LinearLayoutManager) { 
      lastVisibleItemPosition = ((LinearLayoutManager) mLayoutManager).findLastVisibleItemPosition(); 
     } else if (mLayoutManager instanceof GridLayoutManager) { 
      lastVisibleItemPosition = ((GridLayoutManager) mLayoutManager).findLastVisibleItemPosition(); 
     } 

     // If the total item count is zero and the previous isn't, assume the 
     // list is invalidated and should be reset back to initial state 
     if (totalItemCount < previousTotalItemCount) { 
      this.currentPage = this.startingPageIndex; 
      this.previousTotalItemCount = totalItemCount; 
      if (totalItemCount == 0) { 
       this.loading = true; 
      } 
     } 
     // If it’s still loading, we check to see if the dataset count has 
     // changed, if so we conclude it has finished loading and update the current page 
     // number and total item count. 
     if (loading && (totalItemCount > previousTotalItemCount)) { 
      loading = false; 
      previousTotalItemCount = totalItemCount; 
     } 

     // If it isn’t currently loading, we check to see if we have breached 
     // the visibleThreshold and need to reload more data. 
     // If we do need to reload some more data, we execute onLoadMore to fetch the data. 
     // threshold should reflect how many total columns there are too 
     if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) { 
      currentPage++; 
      onLoadMore(currentPage, totalItemCount); 
      loading = true; 
     } 
    } 

    // Defines the process for actually loading more data based on page 
    public abstract void onLoadMore(int page, int totalItemsCount); 

} 

Answer 1

Il vous suffit d'ajouter vos nouvelles données à la dernière position des films de la liste et tout fonctionnera bien. Pour this-

Créer une nouvelle liste comme ArrayList <film> newListMovies et ajouter vos données mises à jour en elle. Maintenant, ajoutez newListMovies dans listMovies et notifier à l'adaptateur. Juste comme ci-dessous-

ArrayList<movie> newListMovies = new ArrayList<>(); 

    // your code.. 

    listMovieHits.addOnScrollListener(new EndlessRecyclerViewScrollListener(linearLayoutManager) { 
     @Override 
     public void onLoadMore(int page, int totalItemsCount) { 
      loadingMore=true; 
      sendJsonRequest(); 

      int currentSize = adapter.getItemCount(); 
      listMovies.addAll(newListMovies); 
      adapter.notifyItemRangeInserted(currentSize, listMovies.size() - 2); 
     } 
    }); 

Espérons que cela aidera.