Question

我的RecyclerView仅显示28个项目。当我向下滚动时，每次加载4个项目。但是，那没关系。当达到28个项目时，将不再加载。数据来自PHP脚本。

编辑：我已经编辑了PHP脚本和try / catch

public class gold extends AppCompatActivity {

private RecyclerView recyclerView;
private GridLayoutManager gridLayoutManager;
private CustomAdapter adapter;
private List<MyData> data_list;

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

    //BackButton
    if(getSupportActionBar()!=null){
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        getSupportActionBar().setDisplayShowHomeEnabled(true);
    }

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    data_list  = new ArrayList<>();
    load_data_from_server(0);

    gridLayoutManager = new GridLayoutManager(this,1);
    recyclerView.setLayoutManager(gridLayoutManager);

    adapter = new CustomAdapter(this,data_list);
    recyclerView.setAdapter(adapter);

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

            if(gridLayoutManager.findLastCompletelyVisibleItemPosition() == data_list.size()-1){
                load_data_from_server(data_list.get(data_list.size()-1).getId());
            }

        }
    });
}

private void load_data_from_server(int id) {

    AsyncTask<Integer,Void,Void> task = new AsyncTask<Integer, Void, Void>() {
        @Override
        protected Void doInBackground(Integer... integers) {

            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder()
                    .url("http://*************.de/script.php?authkey=******="+integers[0])
                    .build();
            try {
                Response response = client.newCall(request).execute();

                JSONArray array = new JSONArray(response.body().string());
                Log.d("Response", response.toString());
                for (int i=0; i<array.length(); i++){

                    JSONObject object = array.getJSONObject(i);

                    MyData data = new MyData(object.getInt("id"),object.getString("playername"),object.getString("gold"),object.getString("currentUser"),object.getString("currentUid"));

                    data_list.add(data);
                }

            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                System.out.println("End of content");
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

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

    task.execute(id);
}
}

这是PHP脚本

$query = "Select * from gold LIMIT 10 OFFSET ($id+1)";

    $result = mysqli_query($connection,$query);

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

        $array[] = $row;    
    }

Answer 1

我解决了我的问题。

这是我的PHP脚本：

$sql = "SELECT * FROM gold ORDER BY id DESC LIMIT $id, 8";
    foreach ($pdo->query($sql) as $row) {
        $array[] = $row;    
    }

    header('Content-Type:Application/json');
    echo json_encode($array);

这是我的代码：

public class gold extends AppCompatActivity {

    private RecyclerView recyclerView;
    private GridLayoutManager gridLayoutManager;
    private CustomAdapter adapter;
    private List<MyData> data_list;
    private Integer countGold;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gold);

        //BackButton
        if(getSupportActionBar()!=null){
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(true);
        }

        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        data_list  = new ArrayList<>();
        load_data_from_server(0);

        gridLayoutManager = new GridLayoutManager(this,1);
        recyclerView.setLayoutManager(gridLayoutManager);

        adapter = new CustomAdapter(this,data_list);
        recyclerView.setAdapter(adapter);

        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {

                if(gridLayoutManager.findLastCompletelyVisibleItemPosition() == data_list.size()-1){
                    load_data_from_server(data_list.size()-1);
                }
            }
        });
    }

    private void load_data_from_server(int id) {

        AsyncTask<Integer,Void,Void> task = new AsyncTask<Integer, Void, Void>() {
            @Override
            protected Void doInBackground(Integer... integers) {

                OkHttpClient client = new OkHttpClient();
                Request request = new Request.Builder()
                        .url("http://************.de/script.php?authkey=*********&id="+integers[0])
                        .build();
                try {
                    Response response = client.newCall(request).execute();


                    Log.d("Response", response.toString());
                    JSONArray array = new JSONArray(response.body().string());

                    for (int i=0; i<array.length(); i++){

                        JSONObject object = array.getJSONObject(i);

                        MyData data = new MyData(object.getInt("id"),object.getString("playername"),object.getString("gold"),object.getString("currentUser"),object.getString("currentUid"));
                        Log.d("Response from Server", object.getString("playername")+"  ||  "+ object.getInt("id"));
                        data_list.add(data);
                    }



                } catch (IOException e) {
                    e.printStackTrace();
                } catch (JSONException e) {
                    System.out.println("End of content");
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }

            @Override
            protected void onPostExecute(Void aVoid) {
                adapter.notifyDataSetChanged();
            }
        };

        task.execute(id);
    }

RecyclerView仅显示28个项目

1 个答案: