RecyclerView'da Sonsuz Kaydırma: Bunu nasıl uygulamalıyım?

Question

Adapters & RecyclerViews ile sonsuz kaydırmayı kodlamak istiyorum ve öğelerimi JSON'dan Volley ile getiriyorum. Bu kılavuzları okudum (Codepath ve github), kendi senaryouma uygulamakta zorlanıyorum. https://example.com/json/items?page=1, https://example.com/json/items?page=2, https://example.com/json/items?page=3 vb

Aşağıda kodları kullanıyorum şunlardır:

benim json url bu biçimi vardır

MainActivity

public class MainActivity extends AppCompatActivity { 

    private final String TAG = "MainActivity"; 

    private int number = 1; 

    //Creating a list of videos 
    private List<VideoItems> mVideoItemsList; 

    //Creating Views 
    private RecyclerView recyclerView; 
    private RecyclerView.Adapter adapter; 
    private RecyclerView.LayoutManager layoutManager; 
    private ProgressDialog mProgressDialog; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Log.d(TAG, "onCreate called"); 

     //Initializing Views 
     recyclerView = (RecyclerView) findViewById(R.id.video_recycler); 
     LinearLayoutManager layoutManager = new LinearLayoutManager(this); 
     recyclerView.setLayoutManager(layoutManager); 


     // This method was copied from codepath (above url) 
     // Add the scroll listener 
     recyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener(layoutManager) { 

      @Override 
      public void onLoadMore(int page, int totalItemsCount) { 
       // Triggered only when new data needs to be appended to the list 
       // Add whatever code needed to append new items of the list 
       customLoadMoreDataFromApi(page); 
      } 
     }); 




     //Initializing the videolist 
     mVideoItemsList = new ArrayList<>(); 
     adapter = new VideoAdapter(mVideoItemsList, this); 

     recyclerView.setAdapter(adapter); 

     if (NetworkCheck.isAvailableAndConnected(this)) { 

      //Calling method to get data 
      getData(); 
     } else { 
      //Codes for building Alert Dialog 
      alertDialogBuilder.setPositiveButton(R.string.alert_retry, new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        if (!NetworkCheck.isAvailableAndConnected(mContext)) { 
         alertDialogBuilder.show(); 
        } else { 
         getData(); 
        } 

       } 
      }); 
      alertDialogBuilder.setNegativeButton(R.string.alert_cancel, new DialogInterface.OnClickListener() { 
       @Override 
       public void onClick(DialogInterface dialog, int which) { 
        finish(); 

       } 
      }); 
      alertDialogBuilder.show(); 

     } 


    } 

    public int getNumber() { 
     return number++; 
    } 

    public void setNumber(int number) { 
     this.number = number; 
    } 

    // This method was copied from codepath (above is url) 
    // Append more data into the adapter 
    // This method probably sends out a network request and appends new data items to your adapter; 
    public void customLoadMoreDataFromApi (int offset) { 
     // Send an API request to retrieve appropriate data using the offset value as a parameter. 
     // Deserialize API request and then construct new objects to append to the adapter. 
     // Add the new objects to the data source for adapter 
     mVideoItemsList.addAll(moreVideos); 
     // For efficiency purpose, notify the adapter of the only elements inserted that got changed 
     // curSize will be equal to the index of the first element inserted because the list is 0-indexed 
     int curSize = adapter.getItemCount(); 
     adapter.notifyItemRangeChanged(curSize, mVideoItemsList.size() - 1); 
    } 

    //This method will get data from the web api 
    private void getData(){ 


     Log.d(TAG, "getData called"); 
     //Codes for Showing progress dialog 

     //Creating a json request 
     JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(ConfigVideo.GET_URL + getNumber(), 
       new Response.Listener<JSONArray>() { 
        @Override 
        public void onResponse(JSONArray response) { 
         Log.d(TAG, "onResponse called"); 
         //Dismissing the progress dialog 
         if (mProgressDialog != null) { 
          mProgressDialog.hide(); 
         } 
        //calling method to parse json array 
         parseData(response); 

        } 
       }, 
       new Response.ErrorListener() { 
        @Override 
        public void onErrorResponse(VolleyError error) { 

        } 
       }); 

     //Creating request queue 
     RequestQueue requestQueue = Volley.newRequestQueue(this); 

     //Adding request to the queue 
     requestQueue.add(jsonArrayRequest); 

    } 

    //This method will parse json data 
    private void parseData(JSONArray array){ 
     Log.d(TAG, "Parsing array"); 

     for(int i = 0; i<array.length(); i++) { 
      VideoItems videoItem = new VideoItems(); 
      JSONObject jsonObject = null; 
      try { 
       jsonObject = array.getJSONObject(i); 
       videoItem.setVideo_title(jsonObject.getString(ConfigVideo.TAG_VIDEO_TITLE)); 
       videoItem.setVideo_body(jsonObject.getString(ConfigVideo.TAG_VIDEO_BODY)); 

      } catch (JSONException w) { 
       w.printStackTrace(); 
      } 
      mVideoItemsList.add(videoItem); 


     } 

     adapter.notifyItemRangeChanged(0, adapter.getItemCount()); 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     Log.d(TAG, "onDestroy called"); 
     if (mProgressDialog != null){ 
      mProgressDialog.dismiss(); 
      Log.d(TAG, "mProgress dialog dismissed"); 

     } 
    } 

} 

EndlessRecyclerViewScrollListener Kodun bağlantısı EndlessRecyclerViewScrollListener.

Projemdeki birimde, onlara gerek duymadığım için GridLayoutManager ve StaggeredGridLayoutManager ile ilgili tüm kodları sildim.

VideoAdapter

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

    private ImageLoader imageLoader; 
    private Context mContext; 

    //List of videos 
    private List<VideoItems> mVideoItems; 

    public VideoAdapter(List<VideoItems> videoItems, Context context) { 
     super(); 

     // Getting all videos 
     this.mVideoItems = videoItems; 
     this.mContext = context; 
    } 

    @Override 
    public ViewHolder onCreateViewHolder (ViewGroup parent, int viewType) { 
     View v = LayoutInflater.from(parent.getContext()) 
       .inflate(R.layout.video_summ, parent, false); 
     ViewHolder viewHolder = new ViewHolder(v); 
     return viewHolder; 
    } 

    @Override 
    public void onBindViewHolder(ViewHolder holder, int position) { 
     VideoItems videoList = mVideoItems.get(position); 
     holder.videoTitle.setText(videoList.getVideo_title()); 
     holder.videoBody.setText(videoList.getVideo_body()); 
    } 


    @Override 
    public int getItemCount(){ 
     //Return the number of items in the data set 
     return mVideoItems.size(); 
    } 

    class ViewHolder extends RecyclerView.ViewHolder { 
     public NetworkImageView videoImage; 
     public TextView videoTitle, videoBody; 

     public ViewHolder (View videoView) { 
      super(videoView); 
      videoTitle = (TextView) videoView.findViewById(R.id.video_title); 
      videoBody = (TextView) videoView.findViewById(R.id.video_body); 
     } 
    } 

} 

VideoItems

public class VideoItems { 
    private String video_title; 
    private String video_body; 

    public String getVideo_title() { 
     return video_title; 
    } 

    public void setVideo_title(String video_title) { 
     this.video_title = video_title; 
    } 

    public String getVideo_body() { 
     return video_body; 
    } 

    public void setVideo_body(String video_body) { 
     this.video_body = video_body; 
    } 
} 

sen bana RecyclerView bunu uygulamak olabilir ipuçları verebilir bilemiyorum. Şimdiden teşekkürler.

Answer 1

Geri dönüştürücüye bağlandığınız bağdaştırıcıya kendi dinleyicisini uygulamanız gerekir. İlk

adapter.setOnLoadMoreListener(new OnLoadMoreListener() { 
      @Override 
      public void onLoadMore() { 
       //get your items here based on the pagination count 
      } 
     }); 

değiştirilen video adaptörü, bu set sizin recyclerview en adaptör olarak,

public interface OnLoadMoreListener { 
    void onLoadMore(); 
} 

böyle bir arayüz oluşturmak

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

    private ImageLoader imageLoader; 
    private Context mContext; 

    //List of videos 
    private List<VideoItems> mVideoItems; 

    private int totalItemCount = 0,lastVisibleItem = 0,int visibleThreshold = 5; 

    private boolean loading; 
     private OnLoadMoreListener onLoadMoreListener; 

    public VideoAdapter(List<VideoItems> videoItems, Context context, RecyclerView recyclerview) { 
     super(); 

     // Getting all videos 
     this.mVideoItems = videoItems; 
     this.mContext = context; 
    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView 
        .getLayoutManager(); 
    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
         @Override 
         public void onScrolled(RecyclerView recyclerView, 
               int dx, int dy) { 
          super.onScrolled(recyclerView, dx, dy); 
          totalItemCount = layoutManager.getItemCount(); 
          lastVisibleItem = layoutManager.findLastVisibleItemPosition(); 
          if (!loading 
            && totalItemCount <= (lastVisibleItem + visibleThreshold)) { 
           if (onLoadMoreListener != null) { 
            onLoadMoreListener.onLoadMore(); 
           } 
           loading = true; 
          } 
         } 
        }); 
    } 

    public void setLoaded() { 
     loading = false; 
    } 

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

    @Override 
    public ViewHolder onCreateViewHolder (ViewGroup parent, int viewType) { 
     View v = LayoutInflater.from(parent.getContext()) 
       .inflate(R.layout.video_summ, parent, false); 
     ViewHolder viewHolder = new ViewHolder(v); 
     return viewHolder; 
    } 

    @Override 
    public void onBindViewHolder(ViewHolder holder, int position) { 
     VideoItems videoList = mVideoItems.get(position); 
     holder.videoTitle.setText(videoList.getVideo_title()); 
     holder.videoBody.setText(videoList.getVideo_body()); 
    } 


    @Override 
    public int getItemCount(){ 
     //Return the number of items in the data set 
     return mVideoItems.size(); 
    } 

    class ViewHolder extends RecyclerView.ViewHolder { 
     public NetworkImageView videoImage; 
     public TextView videoTitle, videoBody; 

     public ViewHolder (View videoView) { 
      super(videoView); 
      videoTitle = (TextView) videoView.findViewById(R.id.video_title); 
      videoBody = (TextView) videoView.findViewById(R.id.video_body); 
     } 
    } 

} 

adaptör gönderme recyclerview nesnesi

başlatılırken

adapter = new VideoAdapter(mVideoItemsList, this, recyclerView); 

012 Eğer öğelerin sonraki seti aldıktan sonra

, senin PAGECOUNT, notifyDataSetChanged() artırmak ve bu size yardımcı olacaktır bu

adapter.setLoaded(); 

umut çağrı!