Wie man endloses Scrollen mit Recycleransicht implementiert

Question

Ich möchte Liste der Daten zeigen, die durch Seiten getrennt sind, die ich zuerst 5 Details zeigen möchte und wenn dann Benutzer scrollt, dann lädt es 5 mehr, indem ich die API wieder rufe, jetzt bin ich gewesen kann die ersten 5 Details anzeigen, aber beim Scrollen ersetzt es die vorherigen 5 durch neue 5 Details, es fügt keine Daten hinzu, sondern ersetzt sie.

Mainfile, in denen möchte ich die Daten zeigen

package com.example.vinod.lcoportal; 


import android.app.ProgressDialog; 
import android.content.Intent; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v7.widget.GridLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
import android.widget.TextView; 

import com.bumptech.glide.Glide; 

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

import java.io.BufferedReader; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.URL; 
import java.util.ArrayList; 


/** 
* A simple {@link Fragment} subclass. 
*/ 
public class StbDetailsFragment extends Fragment { 

    RecyclerView recycler_view_stb_details; 

    ArrayList<StbDetails> listitems_stb = new ArrayList<>(); 
    String[] name = new String[50]; 
    String[] address = new String[100]; 
    String[] vc_stb = new String[100]; 
    String[] city = new String[100]; 
    String[] current_plan = new String[200]; 
    String[] status = new String[50]; 
    String[] csi = new String[300]; 

    int currentpage = 0; 

    int pagesize = 5; 

    ProgressDialog pDialog; 

    JSONArray ja; 
    JSONObject jo; 

    String custcsi, custcity, custname, currentplan, custstatus, vc_no; 

    String stb_url = "http://lco.denonline.in/wapp/Service1.svc/Dashboard"; 


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


    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     // Inflate the layout for this fragment 
     View view = inflater.inflate(R.layout.fragment_stb_details, container, false); 

     currentpage = currentpage + 1; 
     GetStb getStb= new GetStb(currentpage, pagesize); 
     getStb.execute(stb_url); 

     return view; 

    } 

    public class MyAdapterStb extends RecyclerView.Adapter<MyAdapterStb.MyViewHolderStb> { 
     private ArrayList<StbDetails> list; 

     public MyAdapterStb(ArrayList<StbDetails> Data) { 
      list = Data; 
     } 

     @Override 
     public MyViewHolderStb onCreateViewHolder(ViewGroup parent, int viewType) { 
      // create a new view 
      View view = LayoutInflater.from(parent.getContext()) 
        .inflate(R.layout.stb_details_cardview, parent, false); 
      MyViewHolderStb holder = new MyViewHolderStb(view); 
      return holder; 
     } 

     @Override 
     public void onBindViewHolder(final MyViewHolderStb holder, int position) { 

      holder.cust_name.setText(list.get(position).getName()); 
      holder.cust_address.setText(list.get(position).getAddress()); 
      holder.cust_vc.setText(list.get(position).getVc_stb_no()); 
      holder.cust_city.setText(list.get(position).getCity()); 
      holder.cust_plan.setText(list.get(position).getCurrentPlan()); 
      holder.cust_status.setText(list.get(position).getStatus()); 
      // holder.events_imageview.setImageResource(list.get(position).getImageResourceId()); 
      // holder.events_imageview.setTag(list.get(position).getImageResourceId()); 
      // Glide.with(getActivity()).load(list.get(position).getImageResourceId_notices()).into(holder.notices_imageview); 
     } 

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

     public class MyViewHolderStb extends RecyclerView.ViewHolder { 

      TextView cust_name, cust_address, cust_vc, cust_city, cust_plan, cust_status ; 

      public MyViewHolderStb(View v) { 
       super(v); 
       cust_name = (TextView) v.findViewById(R.id.name_stb_details); 
       cust_address = (TextView) v.findViewById(R.id.address_stb_details); 
       cust_vc = (TextView) v.findViewById(R.id.vc_stb_no_stb_details); 
       cust_city = (TextView) v.findViewById(R.id.city_stb_details); 
       cust_plan = (TextView) v.findViewById(R.id.current_plan_stb_details); 
       cust_status = (TextView) v.findViewById(R.id.status_stb_details); 

       // v.setOnClickListener(new View.OnClickListener() { 
       // @Override 
       // public void onClick(View v) { 
       //  Intent i = new Intent(getActivity(),NoticesViewActivity.class); 
       //  i.putExtra("notice_url",pdf[getAdapterPosition()]); 
       //  i.putExtra("notice_title",title_notices[getAdapterPosition()]); 
       //  startActivity(i); 
       // } 
       // }); 

      } 
     } 
    } 

    public void initializeList() { 
     listitems_stb.clear(); 

     for (int i = 0; i < ja.length(); i++) { 

      StbDetails item = new StbDetails(); 
      item.setName(name[i]); 
      item.setAddress(address[i]); 
      item.setVc_stb_no(vc_stb[i]); 
      item.setCity(city[i]); 
      item.setCurrentPlan(current_plan[i]); 
      item.setStatus(status[i]); 
      listitems_stb.add(item); 



     } 


    } 

    public class GetStb extends AsyncTask<String,String,String> { 

     HttpURLConnection httpURLConnection; 

     int CurrentPage, PageSize; 

     public GetStb(int currentpage, int pagesize) { 
      CurrentPage = currentpage; 
      PageSize = pagesize; 
     } 


     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      pDialog = new ProgressDialog(getActivity()); 
      pDialog.setMessage("Fetching Data...Please Wait..."); 
      pDialog.setIndeterminate(false); 
      pDialog.setCancelable(false); 
      pDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); 
      //pDialog.show(); 
      // progress_dialog.setVisibility(View.VISIBLE); 
     } 

     @Override 
     protected String doInBackground(String... params) { 

      try { 
       URL url = new URL(params[0]); 
       Log.d("DoInBackground:URL", url.toString()); 
       //Send Post Data request 
       httpURLConnection = (HttpURLConnection) url.openConnection(); 
       httpURLConnection.setRequestMethod("GET"); 
       httpURLConnection.addRequestProperty("api_key", "XBoGycClZkJrXDVphgpN5c9Bb82fcKQ4"); 
       httpURLConnection.addRequestProperty("gulco", "fe96632f-5173-e611-942d-005056bb1e58"); 
       httpURLConnection.addRequestProperty("currentpage", String.valueOf(CurrentPage)); 
       httpURLConnection.addRequestProperty("pagesize", String.valueOf(PageSize)); 

       //)httpURLConnection.setDoOutput(true); 
       httpURLConnection.setUseCaches(false); 
       httpURLConnection.setDoInput(true); 
       httpURLConnection.connect(); 

       //Get the Server Response 
       InputStream inputStream = httpURLConnection.getInputStream(); 
       BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1")); 
       String response = ""; 
       String line = ""; 

       while ((line = bufferedReader.readLine()) != null) { 
        response += line; 
       } 
       bufferedReader.close(); 
       inputStream.close(); 
       httpURLConnection.disconnect(); 
       Log.d("DoInBackground", "Response:" + response); 
       return response; 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
      return null; 
     } 

     @Override 
     protected void onPostExecute(String response) { 

      GridLayoutManager MyLayoutManager = new GridLayoutManager(getActivity(),1); 
      MyLayoutManager.setOrientation(GridLayoutManager.VERTICAL); 

      recycler_view_stb_details = (RecyclerView) getActivity().findViewById(R.id.recycler_view_stb_details); 
      recycler_view_stb_details.setHasFixedSize(true); 

      try { 
       ja = new JSONArray(response); 
       //ja = jo.getJSONArray("notices"); 
       //images = new String[ja.length()]; 
       //title = new String[ja.length()]; 
       for (int i=0;i<ja.length();i++) { 
        JSONObject json = ja.getJSONObject(i); 
        custcsi = json.getString("CSI"); 
        custcity = json.getString("City"); 
        custname = json.getString("CustName"); 
        currentplan = json.getString("Plan"); 
        custstatus = json.getString("Status"); 
        vc_no = json.getString("VCNO"); 

        name[i] = custname; 
        csi[i] = custcsi; 
        city[i] = custcity; 
        current_plan[i] = currentplan; 
        vc_stb[i] = vc_no; 
        status[i] = custstatus; 

        initializeList(); 
       } 

      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
      //progress_dialog.setVisibility(View.GONE); 

      //pDialog.dismiss(); 

      if (listitems_stb.size() > 0 & recycler_view_stb_details != null) { 
       recycler_view_stb_details.setAdapter(new MyAdapterStb(listitems_stb)); 
      } 
      recycler_view_stb_details.setLayoutManager(MyLayoutManager); 

      //pDialog.dismiss(); 
     } 
    } 
} 

Answer 1

Ich denke, Ihr Problem ist, dass jedes Mal in der public void initializeList() rufen Sie zunächst einmal listitems_stb.clear(); so wird Ihre Liste jedes Mal gelöscht werden, und es werden alle verlieren die vorherigen Daten.

Wenn Sie also andere Elemente zur Liste hinzufügen möchten, sollten Sie sie nicht löschen. Versuchen Sie einfach, listitems_stb.clear(); zu löschen.

Dann für Paginierung siehe diese Antwort here.

hoffe, das hilft