Android JSON解析器加載更多數據

Question

因為我的json源有時會太長，並且如果加載時間太長，我的android應用程序會崩潰，所以我想修改我的代碼，以便當用戶向下滾動以自動加載數據時，或者如果更簡單，我會喜歡添加一個按鈕“加載更多”。 這是我現有的代碼。 添加自動加載或“加載更多”按鈕時，我必須修改什么部分？ 謝謝！

package com.radioxxx.aacplay;

import android.app.DownloadManager;
import android.app.Fragment;
import android.app.ListFragment;
import android.app.ProgressDialog;
import android.content.Context;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;
import android.widget.TextView;

import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class FazeNoi extends ListFragment {
    JSONParser2 jsonParser = new JSONParser2();


    private ProgressDialog pDialog;
    ArrayList<HashMap<String, String>> tracksList;

    JSONArray albums = null;

    String nume_piesa, cale;
    String titlu;

    private static final String URL_ALBUMS = "http://www.radioxxx.ro/json-news";
    private static final String TAG_TITLU = "Titlu";
    private static final String TAG_POZA = "FazeNoiID";
    private static final String TAG_NUME = "CMSdate";
    private static final String TAG_CALE = "URL";



    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        tracksList = new ArrayList<HashMap<String, String>>();

        new LoadTracks().execute();



    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.fragment_fazenoi, container, false);

        return rootView;
    }


    class LoadTracks extends AsyncTask<String, String, String> {


        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(getActivity());
            pDialog.setMessage("Se incarca ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }

        protected String doInBackground(String... args) {
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            //params.add(new BasicNameValuePair(TAG_ID, album_id));

            String json = jsonParser.makeHttpRequest(URL_ALBUMS, "GET",
                    params);

            Log.d("Track List JSON: ", json);

            try {
                JSONArray albums = new JSONArray(json);



                for (int i = 0; i < albums.length(); i++) {
                    JSONObject c = albums.getJSONObject(i);
                    //String poza = c.getJSONArray("PozaPrincipalaMedia").getJSONObject(0).getString("thumb");
                    String track_no = String.valueOf(i + 1);
                    String poza = c.getJSONObject("PozaPrincipalaMedia").getString("thumb");
                    String idpoza = c.getJSONObject("PozaPrincipalaMedia").getString("id");
                    String nume = c.getString(TAG_TITLU);
                    String cale = c.getString(TAG_CALE);



                    HashMap<String, String> map = new HashMap<String, String>();
                    map.put("track_no", track_no + ".");

                    map.put(TAG_POZA, poza);
                    map.put(TAG_NUME, nume);
                    map.put(TAG_CALE, cale);

                    tracksList.add(map);
                }



            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }


        protected void onPostExecute(String file_url) {
            pDialog.dismiss();
            getActivity().runOnUiThread(new Runnable() {
                public void run() {
                    ListAdapter adapter = new SimpleAdapter(
                            getActivity(), tracksList,
                            R.layout.list_faze, new String[] {TAG_POZA, "track_no", TAG_NUME }, new int[] {
                            R.id.list_image,
                            R.id.track_no, R.id.nume_piesa });

                    setListAdapter(adapter);
                    //TextView text = (TextView) getActivity().findViewById(R.id.version);
                    //text.setText(titlu);
                }
            });

        }

    }


}

Answer 1

我將發表評論作為答案，我相信這是快速解決您的問題的最簡單方法。 如果您可以控制在服務器端發送多少JSON ，請從Java應用程序發出第1頁，第2頁等的請求。

頁面1，頁面2等...可以只發送所需的JSON小部分，然后附加一個偵聽器（按鈕/滾動視圖）以請求下一頁，依此類推。 希望這可以幫助！