Ich implementiere ein endloses Datenladen für einen RecyclerView. Wenn die Software erkennt, dass das letzte Element angezeigt wird, lädt sie neue Elemente herunter und ruft das @ auloadMoreData() -Funktion, aber neuer Datensatz wird nicht angezeigt.

Wenn ich @ anrinotifyDataSetChanged() also nichts passiert sein.

Ich habe nur eine Lösung, bei der die Ansicht aktualisiert wird: Setzen Sie den Adapter erneut. Das Problem besteht jedoch darin, dass die Recyclingübersicht an die erste Position zurückkehrt und dann erneut von der ersten zur letzten Position gescrollt wird.

RecyclerViewActivity.java

    RecyclerView rv;

    DatabaseHelpr databaseHelpr;

    RVAdapter adapter;

    LocationFinder locationfinder;

    Location currentLocation;

    ArrayList<ServiceModel> childList, list;

    private int MainService_ID, city_id;

    String url2;

    ActionBar actionBar;

    JSONArray items = null;

    Utility utility;

    Double lat, longi;

    LinearLayoutManager llm;

    int counter=0;

    ProgressBar progressBar;

    private static final String TAG_ITEMS = "items";

    private static final String TAG_LOCALITY = "Locality";

    private static final String TAG_BUSINESS_ID = "Business_Id";

    private static final String TAG_LONGITUDE = "Longitude";

    private static final String TAG_BUSINESS_NAME = "Business_Name";

    private static final String TAG_LATITUDE = "Latitude";


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.recyclerview_activity);

        list = new ArrayList<>();
        utility = new Utility(this);
        llm = new LinearLayoutManager(this);

        Bundle bundle=getIntent().getExtras();
        MainService_ID=bundle.getInt("service_id");
        String mainService_Name = bundle.getString("service_name");
        city_id = bundle.getInt("city_id");
        lat= bundle.getDouble("lat");
        longi=bundle.getDouble("longi");

        rv=(RecyclerView)findViewById(R.id.rv);
        rv.setLayoutManager(llm);

        actionBar = getSupportActionBar();
        assert actionBar != null;
        actionBar.setDisplayHomeAsUpEnabled(true);
        actionBar.setTitle(mainService_Name);

           //Here city_id = 8, lat = 18.552954, longi = 73.897200, counter=0, MainService_ID = 5
           String url="https://servicedata2-dot-indiacomapi.appspot.com/_ah/api/servicedata/v1/ServiceData?city_id=";
           url2 =url+city_id+"&lat="+lat+"&lng="+longi+"&roll="+counter+"&service_id="+MainService_ID;

           AsyncHttpClient client = new AsyncHttpClient();

           progressBar=(ProgressBar) findViewById(R.id.progressBar1);
           progressBar.setVisibility(View.VISIBLE);

           client.get(url2, new AsyncHttpResponseHandler() {

               @Override
               public void onSuccess(int statusCode, Header[] headers, byte[] response) {
                   // called when response HTTP status is "200 OK"
                   String s = new String(response);

                   try {
                       JSONObject jsonObj = new JSONObject(s);

                       // Getting JSON Array node
                       items = jsonObj.getJSONArray(TAG_ITEMS);

                       // looping through All Contacts
                       for (int i = 0; i < items.length(); i++) {

                           JSONObject c = items.getJSONObject(i);
                           String locality = c.getString(TAG_LOCALITY);
                           String business_Id = c.getString(TAG_BUSINESS_ID);
                           String longitude = c.getString(TAG_LONGITUDE);
                           String latitude = c.getString(TAG_LATITUDE);
                           String business_Name = c.getString(TAG_BUSINESS_NAME);
                           locationfinder = new LocationFinder(RecyclerViewActivity.this);
                           // check if GPS enabled
                           if (locationfinder.canGetLocation()) {
                               double lat = locationfinder.getLatitude();
                               double longi = locationfinder.getLongitude();
                               currentLocation = new Location("");
                               currentLocation.setLatitude(lat);
                               currentLocation.setLongitude(longi);
                           } else {
                               locationfinder.showSettingsAlert();
                           }
                           Location savedLocation = new Location("databaseLocation");
                           savedLocation.setLatitude(Double.parseDouble(latitude));
                           savedLocation.setLongitude(Double.parseDouble(longitude));
                           Double difference = currentLocation.distanceTo(savedLocation) * (0.001);
                           difference = Double.parseDouble(new DecimalFormat("##.##").format(difference));
                           String newDifference = String.valueOf(difference) + " km";
                           ServiceModel serviceModel = new ServiceModel(business_Id, business_Name, newDifference, locality);

                           list.add(serviceModel);
                       }
                   } catch (JSONException e) {
                       e.printStackTrace();
                   }

                   progressBar.setVisibility(View.GONE);
                   adapter = new RVAdapter(RecyclerViewActivity.this, list);
                   rv.setAdapter(adapter);
                   rv.addOnScrollListener(new EndlessRecyclerOnScrollListener(llm) {

                       @Override
                       public void onLoadMore(int current_page) {
                           //  counter= counter+1;
                           loadMoreData();
                       }
                   });
               }

               @Override
               public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
                   // called when response HTTP status is "4XX" (eg. 401, 403, 404)
                   //Toast.makeText(getApplicationContext(),""+statusCode,Toast.LENGTH_LONG).show();
               }

           });

    }

    private void loadMoreData() {

        counter= counter+1;

        //Here city_id = 8, lat = 18.552954, longi = 73.897200, counter=1, MainService_ID = 5
        String url="https://servicedata2-dot-indiacomapi.appspot.com/_ah/api/servicedata/v1/ServiceData?city_id=";
        url2 =url+city_id+"&lat="+lat+"&lng="+longi+"&roll="+counter+"&service_id="+MainService_ID;

        AsyncHttpClient client = new AsyncHttpClient();

        progressBar=(ProgressBar) findViewById(R.id.progressBar1);
        progressBar.setVisibility(View.VISIBLE);

        client.get(url2, new AsyncHttpResponseHandler() {

            @Override
            public void onSuccess(int statusCode, Header[] headers, byte[] response) {
                // called when response HTTP status is "200 OK"
                String s = new String(response);

                try {
                    JSONObject jsonObj = new JSONObject(s);

                    // Getting JSON Array node
                    items = jsonObj.getJSONArray(TAG_ITEMS);
                    // looping through All Contacts
                    for (int i = 0; i < items.length(); i++) {
                        JSONObject c = items.getJSONObject(i);
                        String locality = c.getString(TAG_LOCALITY);
                        String business_Id = c.getString(TAG_BUSINESS_ID);
                        String longitude = c.getString(TAG_LONGITUDE);
                        String latitude = c.getString(TAG_LATITUDE);
                        String business_Name = c.getString(TAG_BUSINESS_NAME);
                        locationfinder = new LocationFinder(RecyclerViewActivity.this);
                        // check if GPS enabled
                        if (locationfinder.canGetLocation()) {
                            double lat = locationfinder.getLatitude();
                            double longi = locationfinder.getLongitude();
                            currentLocation = new Location("");
                            currentLocation.setLatitude(lat);
                            currentLocation.setLongitude(longi);
                        } else {
                            locationfinder.showSettingsAlert();
                        }
                        Location savedLocation = new Location("databaseLocation");
                        savedLocation.setLatitude(Double.parseDouble(latitude));
                        savedLocation.setLongitude(Double.parseDouble(longitude));
                        Double difference = currentLocation.distanceTo(savedLocation) * (0.001);
                        difference = Double.parseDouble(new DecimalFormat("##.##").format(difference));
                        String newDifference = String.valueOf(difference) + " km";
                        ServiceModel serviceModel = new ServiceModel(business_Id, business_Name, newDifference, locality);

                        list.add(serviceModel);
                    }
                } catch (JSONException e) {
                    e.prin,tStackTrace();
                }
                progressBar.setVisibility(View.GONE);
                //adapter = new RVAdapter(RecyclerViewActivity.this, list);
                //rv.setAdapter(adapter);
                adapter.notifyDataSetChanged();
            }

            @Override
            public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
            }
        });

        Toast.makeText(this, "Net is present", Toast.LENGTH_SHORT).show();
    }
}  

RVAdapter.java

public class RVAdapter extends RecyclerView.Adapter<RVAdapter.PersonViewHolder>{
    private final LayoutInflater mInflater;
    List<ServiceModel> persons ;
    private Context mContext;


    public RVAdapter(Context context,List<ServiceModel> persons){

       this.mInflater = LayoutInflater.from(context);
        this.persons = new ArrayList<>(persons);
       this.mContext = context;
    }

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
    }

    @Override
    public PersonViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item, viewGroup, false);
        PersonViewHolder pvh = new PersonViewHolder(v);
        return pvh;
    }

    @Override
    public void onBindViewHolder(PersonViewHolder personViewHolder, int i) {
        ServiceModel person = persons.get(i);

        personViewHolder.businessName.setOnClickListener(clickListener);
        personViewHolder.image_url.setOnClickListener(clickListenerImage);

        personViewHolder.businessName.setTag(personViewHolder);
        personViewHolder.difference.setTag(personViewHolder);
        personViewHolder.business_id.setTag(personViewHolder);
        personViewHolder.image_url.setTag(personViewHolder);
        personViewHolder.locality.setTag(personViewHolder);

        personViewHolder.businessName.setText(Html.fromHtml(person.getBusinessname()));
        String firstLetter = String.valueOf(person.getBusinessname().charAt(0));
        ColorGenerators generator = ColorGenerators.MATERIAL; // or use DEFAULT
        int color = generator.getColor(person.getBusinessname());
        TextDrawable drawable = TextDrawable.builder().buildRound(firstLetter, color); // radius in px
        personViewHolder.image_url.setImageDrawable(drawable);
        personViewHolder.difference.setText(Html.fromHtml(person.getNewDiffer()));
        personViewHolder.locality.setText(Html.fromHtml(person.getLocality()));
        personViewHolder.bind(person);
    }

    View.OnClickListener clickListener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            PersonViewHolder holder = (PersonViewHolder) view.getTag();
            int position = holder.getPosition();
            ServiceModel person = persons.get(position);
            String businessids = person.getBusinessid();
            Intent intent = new Intent(mContext, BusinessInfoActivity.class);
            intent.putExtra("businessids", businessids);
            mContext.startActivity(intent);
        }
    };

    View.OnClickListener clickListenerImage = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            PersonViewHolder holder = (PersonViewHolder) view.getTag();
            int position = holder.getPosition();

            ServiceModel person = persons.get(position);
            String businessids = person.getBusinessid();
            Intent intent = new Intent(mContext, BusinessInfoActivity.class);
            intent.putExtra("businessids", businessids);
            mContext.startActivity(intent);
        }
    };

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

    public void animateTo(List<ServiceModel> models) {
        applyAndAnimateRemovals(models);
        applyAndAnimateAdditions(models);
        applyAndAnimateMovedItems(models);
    }

    private void applyAndAnimateRemovals(List<ServiceModel> newModels) {
        for (int i = persons.size() - 1; i >= 0; i--) {
            final ServiceModel model = persons.get(i);
            if (!newModels.contains(model)) {
                removeItem(i);
            }
        }
    }

    private void applyAndAnimateAdditions(List<ServiceModel> newModels) {
        for (int i = 0, count = newModels.size(); i < count; i++) {
            final ServiceModel model = newModels.get(i);
            if (!persons.contains(model)) {
                addItem(i, model);
            }
        }
    }

    private void applyAndAnimateMovedItems(List<ServiceModel> newModels) {
        for (int toPosition = newModels.size() - 1; toPosition >= 0; toPosition--) {
            final ServiceModel model = newModels.get(toPosition);
            final int fromPosition = persons.indexOf(model);
            if (fromPosition >= 0 && fromPosition != toPosition) {
                moveItem(fromPosition, toPosition);
            }
        }
    }

    public ServiceModel removeItem(int position) {
        final ServiceModel model = persons.remove(position);
        notifyItemRemoved(position);
        return model;
    }

    public void addItem(int position, ServiceModel model) {
        persons.add(position, model);
        notifyItemInserted(position);
    }

    public void moveItem(int fromPosition, int toPosition) {
        final ServiceModel model = persons.remove(fromPosition);
        persons.add(toPosition, model);
        notifyItemMoved(fromPosition, toPosition);
    }

    public static class PersonViewHolder extends RecyclerView.ViewHolder {

        protected CardView cv;

        protected TextView businessName, difference, business_id, locality;

        protected ImageView image_url;

        public PersonViewHolder(View itemView) {
            super(itemView);
            cv = (CardView)itemView.findViewById(R.id.cv);
            businessName = (TextView)itemView.findViewById(R.id.business_name);
            difference = (TextView)itemView.findViewById(R.id.txtDifferenece);
            business_id = (TextView)itemView.findViewById(R.id.business_id);
            image_url = (ImageView)itemView.findViewById(R.id.thumbnail);
            locality= (TextView)itemView.findViewById(R.id.txtLocality);
        }

        public void bind(ServiceModel model) {
            businessName.setText(model.getBusinessname());
        }
    }
}  

Bitte hilf mir, wie man @ einstelnotifyDataSetChanged() an den Adapter. In meinem Code funktioniert es nicht. Ich habe bereits alle Antworten überprüft, die auf dem Stackoverflow veröffentlicht sind.