Ich möchte RecyclerView laden mehr Elemente beim Scrollen bis zum Ende. Wie kann ich das bekommen?

Question

Alles war in Ordnung, bis ich entschied, dass die oberste Zeile der Datenbank an der Spitze der Liste stehen würde.

Im Moment ist mein einziges Problem, dass ich RecyclerView mehr Elemente laden möchte, wenn Sie bis zum Ende scrollen.

PHP

Wie schreibe ich den Code in diesem Abschnitt?

$sql= "SELECT * FROM movies_table ORDER BY id DESC"; 

dies complate Code

<?php 
    //Creating a connection 
    $con = mysqli_connect("--","---","----","-----"); 

     /* change character set to utf8 */ 
    $con->set_charset("utf8"); 

    if (mysqli_connect_errno()) 
    { 
     echo "Failed to connect to MySQL: " . mysqli_connect_error(); 
    } 
    /*Get the id of the last visible item in the RecyclerView from the request and store it in a variable. For   the first request id will be zero.*/ 
    $id = $_GET["id"]; 

    $$sql= "SELECT * FROM movies_table ORDER BY id DESC"; 

    $result = mysqli_query($con ,$sql); 

    while ($row = mysqli_fetch_assoc($result)) { 

     $array[] = $row; 

    } 
    header('Content-Type: text/html; charset=utf-8'); 

    echo json_encode($array, JSON_UNESCAPED_UNICODE); 

    mysqli_free_result($result); 

    mysqli_close($con); 

?> 

.

. RecyclerView

.

. Wie schreibe ich den Code in diesem Abschnitt?

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
      @Override 
      public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 



      } 
     }); 
     return view; 
    } 

und dieser Abschnitt

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

JSONObject object = array.getJSONObject(i); 

dies complate Code

public class ThreeFragment extends Fragment{ 

    private static final String TAG = ThreeFragment.class.getSimpleName(); 
    private List<Movie> movies; 
    private RecyclerView recyclerView; 
    private GridLayoutManager gridLayout; 
    private MoviesAdapter adapter; 

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

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

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


     recyclerView = (RecyclerView) view.findViewById(R.id.recyclerview); 
     movies = new ArrayList<>(); 
     getMoviesFromDB(0); 

     gridLayout = new GridLayoutManager(getActivity(), 2); 
     recyclerView.setLayoutManager(gridLayout); 

     adapter = new MoviesAdapter(getActivity(), movies); 
     recyclerView.setAdapter(adapter); 

     recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
      @Override 
      public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 



      } 
     }); 
     return view; 
    } 



    public void fetchTimelineAsync(int page) { 
       // ...the data has come back, add new items to your adapter... 

     movies.clear(); 


     movies = new ArrayList<>(); 

     getMoviesFromDB(0); 

     gridLayout = new GridLayoutManager(getActivity(), 2); 

     recyclerView.setLayoutManager(gridLayout); 

     adapter = new MoviesAdapter(getActivity(), movies); 

     recyclerView.setAdapter(adapter); 

     recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
        @Override 
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 

         if (gridLayout.findLastCompletelyVisibleItemPosition() == movies.size() - 1) { 
          getMoviesFromDB(movies.get(movies.size() - 1).getId()); 
         } 

        } 
       }); 

     adapter.notifyDataSetChanged(); 

     swipeContainer.setRefreshing(false); 
    } 





}private void getMoviesFromDB(int id) { 

    AsyncTask<Integer, Void, Void> asyncTask = new AsyncTask<Integer, Void, Void>() { 



     ProgressDialog pdLoading = new ProgressDialog(getActivity()); 

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

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

     } 


     @Override 
     protected Void doInBackground(Integer... movieIds) { 

      OkHttpClient client = new OkHttpClient(); 
      Request request = new Request.Builder() 
        .url("http://astaneapp.ir/wp-php/movies.php?id=" + movieIds[0]) 
        .build(); 
      try { 
       Response response = client.newCall(request).execute(); 

       JSONArray array = new JSONArray(response.body().string()); 

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

        JSONObject object = array.getJSONObject(i); 

        Movie movie = new Movie(object.getInt("id"), object.getString("movie_name"), 
          object.getString("movie_image"), object.getString("movie_genre") , object.getString("movie_discription") , object.getString("movie_lat"), object.getString("movie_lon") , object.getString("movie_marker")); 

        ThreeFragment.this.movies.add(movie); 
       } 


      } catch (IOException e) { 
       e.printStackTrace(); 
      } catch (JSONException e) { 
       e.printStackTrace(); 
      } 
      return null; 
     } 

     @Override 
     protected void onPostExecute(Void aVoid) { 
      adapter.notifyDataSetChanged(); 
      pdLoading.dismiss(); 
     } 
    }; 

    asyncTask.execute(id); 
} 

Answer 1

Ich habe in meinem Projekt dieses Stück Code unter Verwendung von:

mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
    @Override 
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 
     super.onScrolled(recyclerView, dx, dy); 

     final int totalItemCount = mLinearLayoutManager.getItemCount(); 
     final int visibleItemCount = mLinearLayoutManager.getChildCount(); 
     final int firstVisibleItem = mLinearLayoutManager.findFirstVisibleItemPosition(); 

     if (!mLoadingStarted && (totalItemCount - visibleItemCount <= firstVisibleItem)) { 
      mLoadingStarted = true; 

      // fetch more data 
     } 
    } 
});