RecyclerViewPagination Endless Infinite Scrolling Problem

Question

Ich versuche Endless Infinite Scrolling mit RecyclerView zu implementieren, aber ich bekomme nur alle Datensätze und auch keinen Fortschritt beim Versuch, im unteren Bereich zu scrollen.

dies News_Fragment

public class News_Fragment extends Fragment { 

private List<News> newsList = new ArrayList<>(); 

private TextView textView; 
private RecyclerView recyclerView; 
private NewsAdapter newAdapter; 
private ProgressBar mProgressBar; 

protected Handler handler; 

public News news; 

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

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 

    View rootView = inflater.inflate(R.layout.fragment_news_, container, false); 

    loadData(); 

    handler = new Handler(); 

    recyclerView = (RecyclerView) rootView.findViewById(R.id.News_recycler_view); 

    textView = (TextView)rootView.findViewById(R.id.empty_view); 

    mProgressBar = (ProgressBar) rootView.findViewById(R.id.progressBar); 
    //recyclerView.setLayoutManager(new LinearLayoutManager(getActivity())); 

    recyclerView.setHasFixedSize(true); 

    final LinearLayoutManager mLayoutManager = new LinearLayoutManager(getActivity()); 
    recyclerView.setLayoutManager(mLayoutManager); 
    recyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL_LIST)); 
    recyclerView.setItemAnimator(new DefaultItemAnimator()); 

    recyclerView.setAdapter(newAdapter); 
    newAdapter = new NewsAdapter(newsList,recyclerView); 

    if(newsList.isEmpty()){ 
     recyclerView.setVisibility(View.GONE); 
     textView.setVisibility(View.VISIBLE); 
    }else { 
     recyclerView.setVisibility(View.VISIBLE); 
     textView.setVisibility(View.GONE); 
    } 

    newAdapter.setOnLoadMoreListener(new OnLoadMoreListener() { 
     @Override 
     public void onLoadMore() { 
      //add null , so the adapter will check view_type and show progress bar at bottom 
      newsList.add(null); 
      newAdapter.notifyItemInserted(newsList.size() - 1); 
      handler.postDelayed(new Runnable(){ 
       @Override 
       public void run() { 
        //remove progress item 
        newsList.remove(newsList.size() - 1); 
        newAdapter.notifyItemRemoved(newsList.size()); 

        //add items one bye one 
        int start = newsList.size(); 
        int end = start + 5; 
        for (int i = start + 1;i <= end ; i++) { 

         newsList.add(new News("skip"+start,"limit"+end)); 
         newAdapter.notifyItemInserted(newsList.size()); 
        } 
         newAdapter.setLoaded(); 

       } 
      },2000); 
     } 
    }); 
    JSONObject jsonObject = new JSONObject(); 

    try { 
     jsonObject.put("skip",0); 
     jsonObject.put("limit",50); 
    } catch (JSONException e) { 
     e.printStackTrace(); 
    } 

    new NewsTask() { 
     @Override 
     protected void onPostExecute(APIResponse apiResponse) { 
      if (apiResponse != null && apiResponse.data != null & apiResponse.data.size() > 0) { 
       newsList = apiResponse.data; 
       //newAdapter.notifyDataSetChanged(); 
       newAdapter = new NewsAdapter(newsList,recyclerView); 
       recyclerView.setAdapter(newAdapter); 
      } 
      Log.i("resp", "onPostExecute"); 
      //Hide progressbar 
      mProgressBar.setVisibility(View.GONE); 
     } 
    }.execute(jsonObject); 
    mProgressBar.setVisibility(View.VISIBLE); 
    return rootView; 
} 
//load initial data 
private void loadData(){ 
    int start = newsList.size(); 
    int end = start + 5; 
    for (int i = 1;i<=10;i++){ 

     News news = new News("skip"+i,"limit"+i); 
     newsList.add(0,news); 

    } 
} 

dies NewsTask

public class NewsTask extends AsyncTask<JSONObject, Integer, APIResponse>{ 
ProgressDialog dialog; 
OkHttpClient client = new OkHttpClient(); 
Gson gson = new Gson(); 
private ProgressBar mProgressBar; 
Context context; 

@Override 
protected APIResponse doInBackground(JSONObject... params) { 
    // http://bitstobyte.in/api/news 
    // strat 0 
    // end 10 
    JSONObject jsonObject = params[0]; 

    try { 
     String skip = jsonObject.getString("skip"); 
     String limit = jsonObject.getString("limit"); 
     String url = "http://bitstobyte.in/api/news?query={%22skip%22:"+skip+",%22limit%22:"+limit+"}"; 


     Request request = new Request.Builder().url(url).build(); 
     Response response = client.newCall(request).execute(); 
     if(!response.isSuccessful()){ 
      Log.v("answer","failed"+response.code()); 
      throw new IOException("UnExpected code"+response); 
     } 
     String strResponse = response.body().string(); 
     Log.d("News_Response",strResponse); 

     MainResponse mainResponse = gson.fromJson(strResponse,MainResponse.class); 
     // deserialze and return. 
     return mainResponse.msg; 
    }catch (IOException e) { 
     Log.e("searchTask",e.toString()); 
    } catch (JSONException e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 

}

dies NewsAdapter

public class NewsAdapter extends RecyclerView.Adapter { 
private final int VIEW_ITEM = 1; 
private final int VIEW_PROG = 0; 

private List<News> newsList; 
private Context context; 

// The minimum amount of items to have below your current scroll position 
// before loading more. 
private int visibleThreshold = 5; 
private int lastVisibleItem, totalItemCount; 
private boolean loading; 
private OnLoadMoreListener onLoadMoreListener; 

public NewsAdapter(List<News> newsList , RecyclerView recyclerView){ 
    this.newsList = newsList; 
    this.context = context; 

    if(recyclerView.getLayoutManager() instanceof LinearLayoutManager) { 
     final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager(); 

     recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
      @Override 
      public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 
       super.onScrolled(recyclerView, dx, dy); 
       totalItemCount = linearLayoutManager.getItemCount(); 
       lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition(); 
       if (!loading && totalItemCount <= (lastVisibleItem + visibleThreshold)) { 
        // End has been reached 
        // Do something 
        if (onLoadMoreListener != null) { 
         onLoadMoreListener.onLoadMore(); 
        } 
        loading = true; 
       } 
      } 
      @Override 
      public void onScrollStateChanged(RecyclerView recyclerView, int newState) { 
       super.onScrollStateChanged(recyclerView, newState); 

       // When went to the end of the list, load more posts 
       if (newState == RecyclerView.SCROLL_STATE_IDLE) { 

        if (linearLayoutManager.findLastVisibleItemPosition() >= linearLayoutManager.getItemCount() - 1) { 
         // Grow List 
        } 
       } 
      } 
     }); 
    } 
} 
@Override 
public int getItemViewType(int position){ 
    return newsList.get(position) instanceof News ? VIEW_ITEM : VIEW_PROG; 
} 
@Override 
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) { 
    RecyclerView.ViewHolder vh; 
    if (viewType == VIEW_ITEM) { 
     View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.news_list_row, parent, false); 
     vh = new MyViewHolder(v); 
    } else { 
     View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.progress_item, parent, false); 

     vh = new ProgressViewHolder(v); 
    } 
    return vh; 
} 

public class MyViewHolder extends RecyclerView.ViewHolder { 
    public TextView title; 
    public ImageView image,nextArrowimage; 
    public TextView desc; 
    private News news; 

    public MyViewHolder(View view) { 
     super(view); 
     title = (TextView) view.findViewById(R.id.News_title); 
     image = (ImageView) view.findViewById(R.id.News_imageView); 
     nextArrowimage = (ImageView)view.findViewById(R.id.news_NextArrow); 
     desc = (TextView) view.findViewById(R.id.News_desc); 

     view.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
        String title = news.getTitle(); 
        String desc = news.getDesc(); 
        String image = "http://bitstobyte.in/upload/"+news.getImage(); 

        Intent intent = new Intent(context, News_Activity.class); 
        intent.putExtra("title", title); 
        intent.putExtra("desc",desc); 
        intent.putExtra("imageUrl", image); 
        context.startActivity(intent); 

        Toast.makeText(v.getContext(), "OnClick :" + news.getTitle() + " \n "+news.getImage(),Toast.LENGTH_SHORT).show(); 
      } 
     }); 

    } 
} 

@Override 
public void onBindViewHolder(RecyclerView.ViewHolder holder,int position){ 
    if (holder instanceof MyViewHolder) { 

     final News single_news= (News) newsList.get(position); 

     ((MyViewHolder) holder).title.setText(single_news.getTitle()); 

     ((MyViewHolder) holder).desc.setText(single_news.getDesc()); 

     ((MyViewHolder) holder).nextArrowimage.setImageResource(R.drawable.nextblackbutton); 

     context = ((MyViewHolder) holder).image.getContext(); 

     Picasso.with(context).load("http://bitstobyte.in/upload/"+single_news.getImage()).placeholder(R.drawable.ic_favorite_white_24dp).error(R.drawable.ic_map_24dp).resize(100,100).into(((MyViewHolder) holder).image); 

     ((MyViewHolder) holder).news= single_news; 

    } else { 
     ((ProgressViewHolder) holder).progressBar.setIndeterminate(true); 
    } 
} 
public void setLoaded() { 
    loading = false; 
} 
@Override 
public int getItemCount() { 
    return newsList.size(); 
} 

public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener) { 
    this.onLoadMoreListener = onLoadMoreListener; 
} 

public static class ProgressViewHolder extends RecyclerView.ViewHolder { 
    public ProgressBar progressBar; 

    public ProgressViewHolder(View v) { 
     super(v); 
     progressBar = (ProgressBar) v.findViewById(R.id.progressBar1); 
    } 
} 

}

dies Json Daten

{ 
"status": "ok", 
"msg": { 
    "current": 58, 
    "total": 58, 
    "data": [{ 
     "title": "dfdsfsdf", 
     "machineId": "1bc99f0a-f138-428b-9b54-5531e4c8fc3f", 
     "image": "55a88fbfbc54f41570840e11.jpg", 
     "partnerId": "558be1a2e1d33656b06ddbd7", 
     "_id": "55a88fbfbc54f41570840e11", 
     "desc": "fsfsdfdsfdsf" 
    }, { 
     "title": "one more test", 
     "machineId": "1bc99f0a-f138-428b-9b54-5531e4c8fc3f", 
     "image": "55a8901abc54f41570840e12.jpg", 
     "partnerId": "558be1a2e1d33656b06ddbd7", 
     "_id": "55a8901abc54f41570840e12", 
     "desc": "good.." 
    }, 

Answer 1

ändern getViewType wie diese, wenn Sie Fortschritte wollen bar am Ende der Liste erhalten, während API

@Override 
public int getItemViewType(int position){ 
    return (position >= newsList.size()) ? VIEW_PROG : VIEW_ITEM ; 
} 

aufrufen und eine Größe hinzufügen Fortschritt zeigen

@Override 
    public int getItemCount() { 
     return newsList.size() + 1; 
    } 

@Override 
public void onBindViewHolder(RecyclerView.ViewHolder holder,int position){ 
    if (newsList.get(position)!=null && getItemViewType(position)==VIEW_ITEM) { 

     final News single_news= (News) newsList.get(position); 

     ((MyViewHolder) holder).title.setText(single_news.getTitle()); 

     ((MyViewHolder) holder).desc.setText(single_news.getDesc()); 

     ((MyViewHolder) holder).nextArrowimage.setImageResource(R.drawable.nextblackbutton); 

     context = ((MyViewHolder) holder).image.getContext(); 

     Picasso.with(context).load("http://bitstobyte.in/upload/"+single_news.getImage()).placeholder(R.drawable.ic_favorite_white_24dp).error(R.drawable.ic_map_24dp).resize(100,100).into(((MyViewHolder) holder).image); 

     ((MyViewHolder) holder).news= single_news; 

    } else { 
     ((ProgressViewHolder) holder).progressBar.setIndeterminate(true); 
    } 
}