android - 通过fragment显示JSON数据？

Question

我得到了一个项目:请阅读它

示例 JSON --

[ { "slot":"A", "name":"Dummy Subject 1", "code":"SCD1", "class number":"12345", "total students": "67"}, { "slot":"B", "name":"Dummy Subject 2", "code":"SCD2", "class number":"12346", "total students": "29"}, { "slot":"C", "name":"Dummy Subject 3", "code":"SCD3", "class number":"12347", "total students": "41"}, { "slot":"D", "name":"Dummy Subject 4", "code":"SCD4", "class number":"12348", "total students": "65"}, { "slot":"E", "name":"Dummy Subject 5", "code":"SCD5", "class number":"12349", "total students": "55"} ]

示例 JSON 数据，其中包含 5 个虚拟主题的信息以及与每个主题相关的信息。下载此 JSON 数据，根据您的意愿从中解析信息并存储在共享首选项中。以名称和代码作为标题显示在 ExpandableListView 中。在展开时，显示它的其他细节。

我没能为 N 做到这一点。对象...如果有 n 没有。 JSON数据中的对象....请帮助解决这个问题...

所以我按照说明做了这个项目，但现在我得到了同一个项目，并且在 fragment 中进行，因为#list 项目应该是名称和代码，数据应该是它的数据......

这是我通过使用 Activity 的代码...请告诉我如何使用 fragment 来做同样的事情..

#json_parse_class.java

        package com.office.tracker;
    // Nikhil Verma 13BCE0037 9787029484 L-217
    import java.io.IOException;

    import org.apache.http.HttpEntity;
    import org.apache.http.HttpResponse;
    import org.apache.http.client.ClientProtocolException;
    import org.apache.http.client.HttpClient;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.DefaultHttpClient;
    import org.apache.http.util.EntityUtils;
    import org.json.JSONArray;
    import org.json.JSONException;
    import org.json.JSONObject;

    import android.app.Activity;
    import android.content.Context;
    import android.content.SharedPreferences;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.widget.TextView;
    import android.widget.Toast;

    public class json_dpa extends Activity {
        HttpClient client;
        JSONObject dummy1;
        SharedPreferences json_spref;;
        String[] datas = null;
        TextView tv;
        public static String s1="Default^Default^Default^Default^Default^Default^Default^Default^" +
                "Default^Default^Default^Default^Default^Default^Default^Default^" +
                "Default^Default^Default^Default^Default^Default^Default^Default^Default";
        private static final String SLOT = "slot";
        static final String NAME = "name";
        static final String CODE = "code";
        static final String ClASS_NUMBER = "cno.";
        static final String TOTAL_STUDENTS = "ts";
        static final String TOTAL = "t";
        SharedPreferences.Editor editor;
        public static int ob_counter = 0;
        public String deta[] = null;
        private static final String PREFS_NAME = "json_prefname";
        int count = 0;
        final static String URL = "http://www.gdgvitvellore.com/samplejson/";

        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.json);
            client = new DefaultHttpClient();
            tv = (TextView) findViewById(R.id.json_id);
            json_spref = getSharedPreferences(PREFS_NAME, 0);
        //  this.ob_counter = counter;
        String[] index = { "slot", "name", "code", "class number",
                    "total students" };
            new getdata().execute(index);
        }

        public int  async(int counter) 
        {
        this.ob_counter = counter;
        return 0;
        }

        public JSONObject gdg(int r) throws ClientProtocolException, IOException,
                JSONException {
    ob_counter=r;
            HttpGet get = new HttpGet(URL);
            HttpResponse rtr = client.execute(get);
            int status = rtr.getStatusLine().getStatusCode();
            if (status == 200) {
                HttpEntity e = rtr.getEntity();
                String data = EntityUtils.toString(e);
                JSONArray detail = new JSONArray(data);
                JSONObject dummy = detail.getJSONObject(ob_counter);
                return dummy;
            } else {
                Toast.makeText(json_dpa.this, "Error ", Toast.LENGTH_LONG);
                return null;
            }
        }

        public class getdata extends AsyncTask<String, Integer, String> {

            protected String doInBackground(String... params) {
                try {

                    dummy1 = gdg(0);
                    String mystr1 = dummy1.getString(params[0]);
                    String mystr2 = dummy1.getString(params[1]);
                    String mystr3 = dummy1.getString(params[2]);
                    String mystr4 = dummy1.getString(params[3]);
                    String mystr5 = dummy1.getString(params[4]);
                    dummy1=null;
                    dummy1 = gdg(1);
                    String mystr6 = dummy1.getString(params[0]);
                    String mystr7 = dummy1.getString(params[1]);
                    String mystr8 = dummy1.getString(params[2]);
                    String mystr9 = dummy1.getString(params[3]);
                    String mystr10 = dummy1.getString(params[4]);
                    dummy1=null;
                    dummy1 = gdg(2);
                    String mystr11 = dummy1.getString(params[0]);
                    String mystr12 = dummy1.getString(params[1]);
                    String mystr13 = dummy1.getString(params[2]);
                    String mystr14 = dummy1.getString(params[3]);
                    String mystr15 = dummy1.getString(params[4]);
                    dummy1=null;
                    dummy1 = gdg(3);
                    String mystr16 = dummy1.getString(params[0]);
                    String mystr17 = dummy1.getString(params[1]);
                    String mystr18 = dummy1.getString(params[2]);
                    String mystr19 = dummy1.getString(params[3]);
                    String mystr20 = dummy1.getString(params[4]);
                    dummy1=null;
                    dummy1 = gdg(4);
                    String mystr21 = dummy1.getString(params[0]);
                    String mystr22 = dummy1.getString(params[1]);
                    String mystr23 = dummy1.getString(params[2]);
                    String mystr24 = dummy1.getString(params[3]);
                    String mystr25 = dummy1.getString(params[4]);
                    editor = json_spref.edit();
                    editor.putString(SLOT, mystr1);
                    editor.putString(NAME, mystr2);
                    editor.putString(CODE, mystr3);
                    editor.putString(ClASS_NUMBER, mystr4);
                    editor.putString(TOTAL_STUDENTS, mystr5);
                    editor.putString(TOTAL, mystr1+"^"+mystr2+"^"+mystr3+"^"+mystr4+"^"+mystr5+"^"+mystr6+"^"+mystr7
                            +"^"+mystr8+"^"+mystr9+"^"+mystr10+"^"+mystr11+"^"+mystr12+"^"+mystr13+"^"+mystr14+"^"+mystr15
                            +"^"+mystr16+"^"+mystr17+"^"+mystr18+"^"+mystr19+"^"+mystr20+"^"+mystr21+"^"+mystr22
                            +"^"+mystr23+"^"+mystr24+"^"+mystr25);
                    editor.commit();
                    return mystr1;
                } catch (ClientProtocolException e) {

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

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

                    e.printStackTrace();
                }

                return null;
            }

            protected void onPostExecute(String result) {
                s1 = json_spref.getString(TOTAL, "defaut Slot");
                tv.setText(s1);

            }

        }

    }

list_main class.java

          package com.office.tracker;

      import android.app.Activity;
      import android.content.Intent;
      import android.os.Bundle;
      import android.view.Menu;
      import android.view.MenuInflater;
      import android.view.MenuItem;
      import android.view.View;
      import android.view.Window;
      import android.view.WindowManager;
      import android.view.View.OnClickListener;
      import android.widget.Button;
      import android.widget.ExpandableListView;

      public class json_list_main extends Activity implements OnClickListener
      { // Nikhil Verma 13BCE0037 9787029484 L-217
          ExpandableListView elv;
          Button but;

          protected void onCreate(Bundle savedInstanceState) {

              super.onCreate(savedInstanceState);
              requestWindowFeature(Window.FEATURE_NO_TITLE);
              getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
              setContentView(R.layout.json_exp_list);
              elv=(ExpandableListView) findViewById(R.id.json_exp_listID);
              but=(Button) findViewById(R.id.list_button);
              but.setOnClickListener(this);
              //json_dpa ob=new json_dpa();
              //ob.async(0);

              //String s1=ob.json_spref.getString(ob.NAME, "defaut Slot");
              elv.setAdapter(new json_exp_list_view(this));
          }

          public boolean onCreateOptionsMenu(Menu menu) {
              // TODO Auto-generated method stub
              super.onCreateOptionsMenu(menu);
              MenuInflater mf = getMenuInflater();
              mf.inflate(R.menu.cool_menu, menu);
              return true;
          }

          @Override
          public boolean onOptionsItemSelected(MenuItem item) {
              // TODO Auto-generated method stub
              switch (item.getItemId()) {
              case R.id.aboutus:
                  Intent rob = new Intent("com.office.tracker.ABOUTUS");
                  startActivity(rob);

                  break;
          //    case R.id.preferences:
                  //Intent roby = new Intent("com.office.tracker.PREFS");
                  //startActivity(roby);
                  //break;
              case R.id.exit:
                  finish();
                  break;
              }
              return false;
          }

          public void onClick(View v) {
              if(v.getId()==R.id.list_button){
                  Intent rob = new Intent("com.office.tracker.JSON_DPA");
                  startActivity(rob);

              }

          }

      }




custom adapter class.java




        package com.office.tracker;

    import android.content.Context;
    import android.graphics.Color;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.BaseExpandableListAdapter;
    import android.widget.TextView;

        public class json_exp_list_view extends BaseExpandableListAdapter {
        private Context context;
        int i=0;
        json_dpa ob=new json_dpa();
        String ret=ob.s1;
        String i1="Slot -";
        String i2="Name -";
        String i3="Code -";
        String i4="Class No. -";
        String i5="Total Students -";

        String[] splitArray = ret.split("\\^");//split whenever at least one whitespace is encountered


        //String s1=ob.json_spref.getString(ob.NAME, "defaut Slot");
        //json_dpa ob=new json_dpa();
        //String name1=ob.name_ret();
        //String code1=ob.code_ret();
        String[] parent={i2+splitArray[1]+" , "+i3+splitArray[2],i2+splitArray[6]+" , "+i3+splitArray[7],i2+splitArray[11]+" , "+i3+splitArray[12]
                ,i2+splitArray[16]+" , "+i3+splitArray[17],i2+splitArray[21]+" , "+i3+splitArray[22]};
        String[][] child={{i1+splitArray[0],i4+splitArray[3],splitArray[4]},
                {i1+splitArray[5],i4+splitArray[8],i5+splitArray[9]}
        ,{i1+splitArray[10],i4+splitArray[13],i5+splitArray[14]},
        {i1+splitArray[15],i4+splitArray[18],i5+splitArray[19]},
        {i1+splitArray[20],i4+splitArray[23],i5+splitArray[24]}};
        public json_exp_list_view(Context context) {
            this.context=context;
        }

        @Override
        public Object getChild(int arg0, int arg1) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getChildId(int arg0, int arg1) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        public View getChildView(int GroupPosition, int ChildPosition, boolean arg2, View arg3,
                ViewGroup arg4) {
            TextView tv=new TextView(context);
            tv.setText(child[GroupPosition][ChildPosition]);
            tv.setPadding(90, 15, 15, 15);
            tv.setTextSize(25);
            tv.setTextColor(Color.BLUE);
            return tv;
        }

        @Override
        public int getChildrenCount(int GroupPosition) {
            // TODO Auto-generated method stub
            return child[GroupPosition].length;
        }

        @Override
        public Object getGroup(int GroupPosition) {
            // TODO Auto-generated method stub
            return GroupPosition;
        }

        @Override
        public int getGroupCount() {
            // TODO Auto-generated method stub
            return parent.length;
        }

        @Override
        public long getGroupId(int GroupPosition) {
            // TODO Auto-generated method stub
            return GroupPosition;
        }

        @Override
        public View getGroupView(int GroupPosition, boolean arg1, View arg2, ViewGroup arg3) {

            TextView tv=new TextView(context);
            tv.setText(parent[GroupPosition]);
            tv.setPadding(110, 15, 15, 15);
            tv.setTextSize(27);
            tv.setTextColor(Color.GREEN);
            return tv;
        }

        @Override
        public boolean hasStableIds() {
            // TODO Auto-generated method stub
            return false;
        }

        @Override
        public boolean isChildSelectable(int arg0, int arg1) {
            // TODO Auto-generated method stub
            return true;
        }

    }

Answer 1

要将您的 JSON 字符串转换为对象，您需要执行以下操作:

转到以下链接并下载 GSON: https://code.google.com/p/google-gson/downloads/detail?name=google-gson-1.5-release.zip&can=4&q=

复制到你的项目中

创建表示主题列表的类

在需要将 JSON 转换为主题列表的地方，请在代码中执行以下操作:

//import the packeges

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.tekpub.models.Production;

//type of objct we need to convert JSON string to
Type typeOfDest = new TypeToken<List<Subjects>>(){}.getType();

Gson gson = new Gson(); 
//return the object     
return gson.fromJson(input, typeOfDest);