wie bearbeiten? unendlich recycleview

Question

ich mache unendlich recycleview mit json.
dieser Code funktioniert nur zur Hälfte
Ich kann die Elemente zum ersten Mal geladen sehen.
aber wenn ich scroll,
nichts passieren, ich denke, vielleicht onLoadMore() funktioniert nicht.
ich wurde bearbeitet 4hours
dirigiere mich
wo soll ich bearbeiten?
Vielen Dank für Ihr Interesse.

MainActivity

package com.androidcss.jsonexample; 

import android.app.ProgressDialog; 
import android.os.AsyncTask; 
import android.os.Handler; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.widget.Toast; 
import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 
import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.MalformedURLException; 
import java.net.URL; 
import java.util.ArrayList; 
import java.util.List; 

public class MainActivity extends AppCompatActivity { 

    // CONNECTION_TIMEOUT and READ_TIMEOUT are in milliseconds 
    public static final int CONNECTION_TIMEOUT = 10000; 
    public static final int READ_TIMEOUT = 15000; 
    private RecyclerView mRVFishPrice; 
    private AdapterFish mAdapter; 
    protected Handler handler; 
    List<DataFish> data=new ArrayList<>(); 

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


     //Make call to AsyncTask 
     new AsyncLogin().execute(); 


     handler = new Handler(); 

     mRVFishPrice = (RecyclerView)findViewById(R.id.fishPriceList); 
     mAdapter = new AdapterFish(MainActivity.this, data, mRVFishPrice); 
     mRVFishPrice.setAdapter(mAdapter); 
     mRVFishPrice.setLayoutManager(new  LinearLayoutManager(MainActivity.this)); 

     mAdapter.setOnLoadMoreListener(new AdapterFish.OnLoadMoreListener() { 

      @Override 
      public void onLoadMore() { 

       //add progress item 
       data.add(null); 
       mAdapter.notifyItemInserted(data.size() - 1); 

       handler.postDelayed(new Runnable() { 

        @Override 
        public void run() { 

         new AsyncLogin().execute(); 

        } 

       }, 2000); 

       System.out.println("load"); 
      } 

     }); 

    } 

    private class AsyncLogin extends AsyncTask<String, String, String> { 
     ProgressDialog pdLoading = new ProgressDialog(MainActivity.this); 
     HttpURLConnection conn; 
     URL url = null; 

     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 

      //this method will be running on UI thread 
      pdLoading.setMessage("\tLoading..."); 
      pdLoading.setCancelable(false); 
      pdLoading.show(); 

     } 

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

       // Enter URL address where your json file resides 
       // Even you can make call to php file which returns json data 
       url = new URL("http://10.0.2.2/test/example.json"); 

      } catch (MalformedURLException e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
       return e.toString(); 
      } 
      try { 

       // Setup HttpURLConnection class to send and receive data from php and mysql 
       conn = (HttpURLConnection) url.openConnection(); 
       conn.setReadTimeout(READ_TIMEOUT); 
       conn.setConnectTimeout(CONNECTION_TIMEOUT); 
       conn.setRequestMethod("GET"); 

       // setDoOutput to true as we recieve data from json file 
       conn.setDoOutput(true); 

      } catch (IOException e1) { 
       // TODO Auto-generated catch block 
       e1.printStackTrace(); 
       return e1.toString(); 
      } 

      try { 

       int response_code = conn.getResponseCode(); 

       // Check if successful connection made 
       if (response_code == HttpURLConnection.HTTP_OK) { 

        // Read data sent from server 
        InputStream input = conn.getInputStream(); 
        BufferedReader reader = new BufferedReader(new InputStreamReader(input)); 
        StringBuilder result = new StringBuilder(); 
        String line; 

        while ((line = reader.readLine()) != null) { 
         result.append(line); 
        } 

        // Pass data to onPostExecute method 
        return (result.toString()); 

       } else { 

        return ("unsuccessful"); 
       } 

      } catch (IOException e) { 
       e.printStackTrace(); 
       return e.toString(); 
      } finally { 
       conn.disconnect(); 
      } 


     } 

     @Override 
     protected void onPostExecute(String result) { 

      //this method will be running on UI thread 

      pdLoading.dismiss(); 
      List<DataFish> data=new ArrayList<>(); 

      pdLoading.dismiss(); 
      try { 

       JSONArray jArray = new JSONArray(result); 

       // Extract data from json and store into ArrayList as class objects 
       for(int i=0;i<jArray.length();i++){ 
        JSONObject json_data = jArray.getJSONObject(i); 
        DataFish fishData = new DataFish(); 
        fishData.fishImage= json_data.getString("fish_img"); 
        fishData.fishName= json_data.getString("fish_name"); 
        fishData.catName= json_data.getString("cat_name"); 
        fishData.sizeName= json_data.getString("size_name"); 
        fishData.price= json_data.getInt("price"); 
        data.add(fishData); 
       } 

        // Setup and Handover data to recyclerview 
        mRVFishPrice = (RecyclerView)findViewById(R.id.fishPriceList); 
        mAdapter = new AdapterFish(MainActivity.this, data, mRVFishPrice); 
        mRVFishPrice.setAdapter(mAdapter); 
        mRVFishPrice.setLayoutManager(new LinearLayoutManager(MainActivity.this)); 

      } catch (JSONException e) { 
       Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show(); 
      } 

     } 

    } 
} 

AdapterFish.java

package com.androidcss.jsonexample; 

import android.content.Context; 
import android.support.v4.content.ContextCompat; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ImageView; 
import android.widget.ProgressBar; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.bumptech.glide.Glide; 
import java.util.Collections; 
import java.util.List; 

public class AdapterFish extends RecyclerView.Adapter<RecyclerView.ViewHolder> { 

    private Context context; 
    final private Context context2 = context; 
    private LayoutInflater inflater; 
    List<DataFish> data= Collections.emptyList(); 
    DataFish current; 
    int currentPos=0; 



    private final int VIEW_ITEM = 1; 
    private final int VIEW_PROG = 0; 


    // The minimum amount of items to have below your current scroll position before loading more. 
    private int visibleThreshold = 2; 
    private int lastVisibleItem, totalItemCount; 
    private boolean loading; 
    private OnLoadMoreListener onLoadMoreListener; 



    // create constructor to innitilize context and data sent from MainActivity 
    public AdapterFish(Context context, List<DataFish> data, RecyclerView recyclerView){ 
     this.context=context; 
     inflater= LayoutInflater.from(context); 
     this.data=data; 

     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 int getItemViewType(int position) { 
     return data.get(position) != null ? VIEW_ITEM : VIEW_PROG; 
    } 


    // Inflate the layout when viewholder created 
    @Override 
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 

     MyViewHolder holder; 

     if (viewType == VIEW_ITEM) { 

      View view = inflater.inflate(R.layout.container_fish, parent, false); 
      holder = new MyViewHolder(view); 

     } 
     else 
     { 
      View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.progressbar_item, parent, false); 
      RecyclerView.ViewHolder vh = new ProgressViewHolder(v); 

      return vh; 
     } 

    return holder; 
    } 

    // Bind data 
    @Override 
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { 

     // Get current position of item in recyclerview to bind data and assign values from list 
     MyViewHolder myHolder= (MyViewHolder) holder; 
     DataFish current=data.get(position); 
     myHolder.textFishName.setText(current.fishName); 
     myHolder.textSize.setText("Size: " + current.sizeName); 
     myHolder.textType.setText("Category: " + current.catName); 
     myHolder.textPrice.setText("Rs. " + current.price + "\\Kg"); 
     myHolder.textPrice.setTextColor(ContextCompat.getColor(context, R.color.colorAccent)); 

     // load image into imageview using glide 
     Glide.with(context).load("http://192.168.1.7/test/images/" + current.fishImage) 
      .placeholder(R.drawable.ic_img_error) 
      .error(R.drawable.ic_img_error) 
      .into(myHolder.ivFish); 

    } 

    public void setLoaded() { 
     loading = false; 
    } 

    // return total item from List 
    @Override 
    public int getItemCount() { 
     return data.size(); 
    } 

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

    public interface OnLoadMoreListener { 
     void onLoadMore(); 
    } 

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

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


     class MyViewHolder extends RecyclerView.ViewHolder{ 

     TextView textFishName; 
     ImageView ivFish; 
     TextView textSize; 
     TextView textType; 
     TextView textPrice; 

     // create constructor to get widget reference 
     public MyViewHolder(View itemView) { 
      super(itemView); 
      textFishName= (TextView) itemView.findViewById(R.id.textFishName); 
      ivFish= (ImageView) itemView.findViewById(R.id.ivFish); 
      textSize = (TextView) itemView.findViewById(R.id.textSize); 
      textType = (TextView) itemView.findViewById(R.id.textType); 
      textPrice = (TextView) itemView.findViewById(R.id.textPrice); 
     } 

    } 

} 

Answer 1

Ich kann meine eigene Methode zum Laden mehr Einzelteile geben. Sie haben eine eigene abstrakte Klasse erstellen ScrollRecycler genannt, die sich von RecyclerView.OnScrollListener.Here erstreckt es UMSETZEN

public abstract class ScrollRecycler extends RecyclerView.OnScrollListener { 
int page = 0; 
// The current offset index of data you have loaded 
int startingPageIndex = 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; 

RecyclerView.LayoutManager mLayoutManager; 

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

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(); 
    } 
    // 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) { 
     page = 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 
    int visibleThreshold = 10; 
    if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) { 
     page++; 
     onLoadMore(page); 
     loading = true; 
    } 
} 
public abstract void onLoadMore(final int page); 

Und Sie haben Ihre abstrakten Klasse zu Ihrem RecyclerView nicht Adapter hinzuzufügen.

public class MainActivity extends AppCompatActivity { 

// CONNECTION_TIMEOUT and READ_TIMEOUT are in milliseconds 
public static final int CONNECTION_TIMEOUT = 10000; 
public static final int READ_TIMEOUT = 15000; 
private RecyclerView mRVFishPrice; 
private AdapterFish mAdapter; 
protected Handler handler; 
List<DataFish> data=new ArrayList<>(); 

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


    //Make call to AsyncTask 
    new AsyncLogin().execute(); 


    handler = new Handler(); 

    mRVFishPrice = (RecyclerView)findViewById(R.id.fishPriceList); 
    mAdapter = new AdapterFish(MainActivity.this, data, mRVFishPrice); 
    mRVFishPrice.setAdapter(mAdapter); 
    mRVFishPrice.setLayoutManager(new LinearLayoutManager(MainActivity.this)); 
    mRVFishPrice.addOnScrollListener(new ScrollRecycler(new LinearLayoutManager(MainActivity.this)) { 
     @Override 
     public void onLoadMore(int page) { 
      // you can make network call to Server in order to retrive data here page is comminh 
     } 
    }); 


} 

ich denke, es wird Ihnen helfen,

Answer 2

Hier ist mein Code für Fragment

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    view = inflater.inflate(R.layout.fragment_all, container, false); 
    ButterKnife.bind(this, view); 
    fab = (FloatingActionButton) view.findViewById(R.id.fab_fragment_all); 
    type = getArguments().getString("type"); 
    if(type.equals(Utils.TYPE_JOURNAL)){ 
     fab.show(); 
     fab.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       makeSubscribeForJournal(); 
      } 
     }); 
    }else{ 
     fab.hide(); 
    } 
    category_name = getArguments().getString("category_name"); 
    manager = new LinearLayoutManager(getContext()); 
    adapter = new AllAdapter(getContext(), onArticleClickListener); 
    recyclerView.setLayoutManager(manager); 
    recyclerView.setAdapter(adapter); 
    swipe.post(new Runnable() { 
     @Override 
     public void run() { 
      swipe.setRefreshing(true); 
      makeCall(1, category_name,type); 
     } 
    }); 
    swipe.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() { 
     @Override 
     public void onRefresh() { 
      swipe.setRefreshing(false); 
     } 
    }); 

    recyclerView.addOnScrollListener(new ScrollRecycler(manager, type) { 
     @Override 
     public void onLoadMore(int page) { 
      makeCall(page, category_name,type); 
     } 
    }); 
    return view; 
} 

Hier ist meine ScrollRecycler abstrakte Klasse, die wie Sie gleich ist.

public abstract class ScrollRecycler extends RecyclerView.OnScrollListener { 
int page = 1; 
// The current offset index of data you have loaded 
int startingPageIndex = 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; 
String type; 
RecyclerView.LayoutManager mLayoutManager; 

public ScrollRecycler(LinearLayoutManager layoutManager ,String type) { 
    this.mLayoutManager = layoutManager; 
    this.type= type; 
} 

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(type.equals(Utils.TYPE_JOURNAL)) { 
     if (dy > 0) { 
      AllFragment.fab.hide(); 
     } else { 
      AllFragment.fab.show(); 
     } 
    } 
    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(); 
    } 
    // 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) { 
     page = 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 
    int visibleThreshold = 10; 
    if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) { 
     page++; 
     onLoadMore(page); 
     loading = true; 
    } 
} 
public abstract void onLoadMore(final int page); 

}