二级列表ExpendableListView实现从网络上获取数据

二级列表ExpendableListView实例

效果如下图所示：

获取数据地址：url：http://www.handybest.com/index.php?m=Wx&c=Index&a=get_topic_info&id=34&view=
（个人使用 禁止商业使用）

1.首先创建二级列表的JavaBean类 ；

2.访问网址请求数据，使用Gson解析json串，代码如下：

package com.example.aa;import android.util.Log;import com.google.gson.Gson;import com.google.gson.JsonSyntaxException;import java.io.BufferedInputStream;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;import java.util.Scanner;public class ExUtils {    private static final String TAG_GET = "exutils--->";    public static String connectGet() {        HttpURLConnection urlConnection = null;        try {            URL url = new URL("http://www.handybest.com/index.php?m=Wx&c=Index&a=get_topic_info&id=34&view=");            urlConnection = (HttpURLConnection) url.openConnection();            InputStream in = new BufferedInputStream(urlConnection.getInputStream());            // 判断请求是否成功            if (urlConnection.getResponseCode() == 200) {//                // 获取返回的数据//                byte[] data = readStream(urlConnection.getInputStream());//                Log.i(TAG_GET, "Get方式请求成功，返回数据如下：");//                Log.i(TAG_GET, new String(data, "UTF-8"));//                return new String(data, "UTF-8");                return readInStreams(in);            } else {                Log.i(TAG_GET, "Get方式请求失败");            }        } catch (Exception e) {            e.printStackTrace();        } finally {            urlConnection.disconnect();        }        return null;    }    private static String readInStreams(InputStream in) {        Scanner scanner = new Scanner(in).useDelimiter("\\A");        return scanner.hasNext() ? scanner.next() : "";    }    /***     * Gson 解析数据     */    public static LcBean gsonData() {        LcBean lcBean = null;        try {            String strContent = connectGet();            Gson gson = new Gson();            lcBean = gson.fromJson(strContent, LcBean.class);            return lcBean;        } catch (JsonSyntaxException e) {            // TODO Auto-generated catch block            e.printStackTrace();        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }        return null;    }}

3.最重要的功能块出现，实现一级列表，二级列表数据的添加：

1）为一级列表添加数据方法：

 public List<DetailsBean>   detailsList= ExUtils.gsonData().getData().getDetails();          public ArrayList<String> getGeneralsTypes(){              ArrayList<String> generalsTypes=new ArrayList<String>();              for(int i=0;i<detailsList.size();i++){                generalsTypes.add(detailsList.get(i).getTag_title());            }            return generalsTypes;          }          private ArrayList<String> generalsTypes=getGeneralsTypes();

2）为二级列表添加数据

public ArrayList<ArrayList<DetailsBean.PictBean>> getGenerals(){             // Objects[][] objectsesGener=new Objects[detailsList.size()][];              ArrayList<ArrayList<DetailsBean.PictBean>> generalss = new  ArrayList<ArrayList<DetailsBean.PictBean>>();              for (int i=0;i<detailsList.size();i++){                  DetailsBean detailsBean = detailsList.get(i);                  List<DetailsBean.PictBean> pict = detailsBean.getPict();                  ArrayList<DetailsBean.PictBean> dpict=new ArrayList<DetailsBean.PictBean>();                  for (int j=0;j<pict.size();j++){                      dpict.add(pict.get(j));                  }                  generalss.add(dpict);              }              Log.i("exutils---2>",generalss.toString());              return generalss;          }          private ArrayList<ArrayList<DetailsBean.PictBean>> generals=getGenerals();

4.ExpandableListAdapter中的实现如下：

      final ExpandableListAdapter adapter = new BaseExpandableListAdapter() {          //设置组视图的图片//          int[] logos = new int[] { R.drawable.ic_launcher, R.drawable.ic_launcher,R.drawable.ic_launcher};          //          private String [][] generals=ExUtils.getItemChild();          //子视图图片          /*public int[][] generallogos = new int[][] {                  { R.drawable.ic_launcher, R.drawable.ic_launcher,                          R.drawable.ic_launcher, R.drawable.ic_launcher,                          R.drawable.ic_launcher, R.drawable.ic_launcher },                  { R.drawable.ic_launcher, R.drawable.ic_launcher,                          R.drawable.ic_launcher, R.drawable.ic_launcher,                          R.drawable.ic_launcher, R.drawable.ic_launcher },                  { R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher,                          R.drawable.ic_launcher, R.drawable.ic_launcher } };*/          public List<DetailsBean>  detailsList= ExUtils.gsonData().getData().getDetails();            /**一级列表数据**/          public ArrayList<String> getGeneralsTypes(){              ArrayList<String> generalsTypes=new ArrayList<String>();              for(int i=0;i<detailsList.size();i++){                generalsTypes.add(detailsList.get(i).getTag_title());            }            return generalsTypes;          }          private ArrayList<String> generalsTypes=getGeneralsTypes();          /**二级列表数据**/          public ArrayList<ArrayList<DetailsBean.PictBean>> getGenerals(){             // Objects[][] objectsesGener=new Objects[detailsList.size()][];              ArrayList<ArrayList<DetailsBean.PictBean>> generalss = new  ArrayList<ArrayList<DetailsBean.PictBean>>();              for (int i=0;i<detailsList.size();i++){                  DetailsBean detailsBean = detailsList.get(i);                  List<DetailsBean.PictBean> pict = detailsBean.getPict();                  ArrayList<DetailsBean.PictBean> dpict=new ArrayList<DetailsBean.PictBean>();                  for (int j=0;j<pict.size();j++){                      dpict.add(pict.get(j));                  }                  generalss.add(dpict);              }              Log.i("exutils---2>",generalss.toString());              return generalss;          }          private ArrayList<ArrayList<DetailsBean.PictBean>> generals=getGenerals();          //自己定义一个获得文字信息的方法          TextView getTextView() {              AbsListView.LayoutParams lp = new AbsListView.LayoutParams(                      ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);              TextView textView = new TextView(                      MainActivity.this);              textView.setLayoutParams(lp);              textView.setGravity(Gravity.CENTER_VERTICAL);              textView.setPadding(36, 0, 0, 0);              textView.setTextSize(20);              textView.setTextColor(Color.BLACK);              return textView;          }          //重写ExpandableListAdapter中的各个方法          @Override          public int getGroupCount() {              // TODO Auto-generated method stub              return generalsTypes.size();          }          @Override          public Object getGroup(int groupPosition) {              // TODO Auto-generated method stub              return generalsTypes.get(groupPosition);          }          @Override          public long getGroupId(int groupPosition) {              // TODO Auto-generated method stub              return groupPosition;          }          @Override          public int getChildrenCount(int groupPosition) {              // TODO Auto-generated method stub              return generals.get(groupPosition).size();          }          @Override          public DetailsBean.PictBean getChild(int groupPosition, int childPosition) {              // TODO Auto-generated method stub              return    generals.get(groupPosition).get(childPosition);          }          @Override          public long getChildId(int groupPosition, int childPosition) {              // TODO Auto-generated method stub              return childPosition;          }          @Override          public boolean hasStableIds() {              // TODO Auto-generated method stub              return true;          }          @Override          public View getGroupView(int groupPosition, boolean isExpanded,                                   View convertView, ViewGroup parent) {              // TODO Auto-generated method stub              LinearLayout ll = new LinearLayout(                      MainActivity.this);//              ll.setOrientation(0);              ImageView logo = new ImageView(MainActivity.this);//              logo.setImageResource(logos[groupPosition]);              logo.setPadding(50, 0, 0, 0);              ll.addView(logo);              TextView textView = getTextView();              textView.setTextColor(Color.BLACK);              textView.setText(getGroup(groupPosition).toString());              ll.addView(textView);              return ll;          }          @Override          public View getChildView(int groupPosition, int childPosition,                                   boolean isLastChild, View convertView, ViewGroup parent) {              // TODO Auto-generated method stub              LinearLayout ll = new LinearLayout(                      MainActivity.this);//              ll.setOrientation(0);//              ImageView generallogo = new ImageView(//                      MainActivity.this);//              generallogo//                      .setImageResource(generallogos[groupPosition][childPosition]);//              ll.addView(generallogo);              TextView textView = getTextView();              textView.setText(getChild(groupPosition, childPosition).getContent());              ll.addView(textView);              Log.i("exutils---1>","groupPosition+childPosition=["+groupPosition+","+childPosition+"]");              Log.i("exutils---1>",getChild(groupPosition, childPosition).getContent());              return ll;          }          @Override          public boolean isChildSelectable(int groupPosition,                                           int childPosition) {              // TODO Auto-generated method stub              return true;          }      };

1. 最后在MainActivity中将数据添加到视图view上显示出来：

 ExpandableListView expandableListView = (ExpandableListView) findViewById(R.id.list);      expandableListView.setAdapter(adapter);      //设置item点击的监听器      expandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {          @Override          public boolean onChildClick(ExpandableListView parent, View v,                                      int groupPosition, int childPosition, long id) {              Toast.makeText(                      MainActivity.this,                      "你点击了" + adapter.getChild(groupPosition, childPosition),                      Toast.LENGTH_SHORT).show();              return false;          }      });      }

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