android - 在 android 中滚动时使用改造从 API 获取下 10 个项目的分页

Question

在 android 中滚动时使用改造从 API 获取下 10 个项目的分页

Answer 1

相反，

如果您使用带有 BaseAdapter 的简单 ListView ，则用于分页，那么你可以按照下面的代码。

使用 2 arrayList 进行分页。一种是加载所有listview项(allDataList)，一种是在adapter中设置10项(paginationList)。

首先使用retrofit加载allDataList中的所有数据。

public static int itemsCount = 10; 
     //i need pagination of 10 records, so here i passed 10, you may increase this no. here as your requirement.

ArrayList<User_pojo> allDataList, paginationList;
Adapter_UserList adapter;
ListView listViewUser;
View footerView;
LayoutInflater layoutInflater;
int lastItem,preLast;
Context context;

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

        context = this;
        listViewUser = (ListView) findViewById(R.id.listViewUser);

        allDataList = new ArrayList<>();
        paginationList = new ArrayList<>();
        layoutInflater = LayoutInflater.from(context);
        footerView = layoutInflater.inflate(R.layout.load_more_view, null);
        listViewUser.addFooterView(footerView);

        Call_api();

        listViewUser.setOnScrollListener(new AbsListView.OnScrollListener() {

       @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {

        }

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

           lastItem = (firstVisibleItem + visibleItemCount);
            if (lastItem == totalItemCount) {
                if (preLast != lastItem) {
                    //to avoid multiple calls for last item

                    preLast = lastItem;

                    footerView.findViewById(R.id.progress_bar).setVisibility(View.VISIBLE);
                    footerView.postDelayed(new Runnable() {
                        @Override
                        public void run() {
                            itemsCount += 10;
                            LoadMoreList();
                            listViewUser.setSelection(lastItem - 1); //to display more loaded records @ current displayed position.
                        }
                    }, 1500);
                }
            }
        }
    });

    }


    @Override
    public void onStart() {
      super.onStart();
      LoadMoreList();

    }

public interface AppService{

    @FormUrlEncoded
    @POST("getUserList")
    Call<User_pojo> getUserList(@FieldMap(encoded = true) Map<String, String> map);

}       

void Call_api() {

    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl("http://your_api_url_here.com/")
            .addConverterFactory(GsonConverterFactory.create())
            .build();


    Call<User_pojo> call = retrofit.create(AppService.class).getUserList(getUserMap());

    call.enqueue(new Callback<User_pojo>() {
        @Override
        public void onResponse(Call<User_pojo> call, Response<User_pojo> response) {
            Log.e("Response", new Gson().toJson(response.body()));
            if (response.body().getResponse().equalsIgnoreCase("true")) {
                allDataList = response.body().getData();
                Log.e("size", allDataList.size() + "");
                LoadMoreList();
            }
        }

        @Override
        public void onFailure(Call<User_pojo> call, Throwable t) {
            t.printStackTrace();
            t.getMessage();
            Log.e("Failed", t.getMessage());
        }
    });
}

    private void LoadMoreList() {
    try {
        Log.e("size", String.valueOf(allDataList.size()));
        if (allDataList.size() >= itemsCount) {
            paginationList.clear();
            for (int i = 0; i < itemsCount; i++) {
                paginationList.add(allDataList.get(i));
            }
            Log.e("paginationList_Size", String.valueOf(paginationList.size()));
            adapter = new Adapter_UserList(context, paginationList);
        } else {
            adapter = new Adapter_UserList(context, allDataList);
            listViewUser.removeFooterView(footerView); // loaded all list then simply remove footerView.
        }

        if (footerView != null)
            footerView.findViewById(R.id.progress_bar).setVisibility(View.INVISIBLE);

        listViewUser.setAdapter(adapter);
    } catch (Exception ignored) {

    }
}


private Map<String, String> getUserMap() {
    Map<String, String> map = new HashMap<>();
    map.put("uid", "001");
    map.put("token", "5526");

    Log.e("logs", map.toString());
    return map;
}

希望这对您有所帮助。