android - 如何制作动态可扩展 ListView ？

Question

我正在制作一个动态的可扩展 ListView ，我想在其中显示标题(父级)中的标题和父级中的其他值，这意味着子级。我能够从服务器获取值(value)并希望在可扩展 ListView 中显示该值。我可以在 Header 中设置名称，但我无法在 child 中显示其他值，我应该怎么做，请帮助我。

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这是Activity中的代码

public class Pxe extends Activity {

    ExpandableListAdapter listAdapter;
    ExpandableListView expListView;
    List<String> listDataHeader;
    HashMap<String, List<String>> listDataChild;
    String myJSON,company_name,from_date,to_date,location,fire_id,guard_number;
    JSONArray peoples = null;


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

        // get the listview
        expListView = (ExpandableListView) findViewById(R.id.lvExp);

        // preparing list data
       // prepareListData();
        getProp();

    }




    public void getProp(){
        class GetDataJSON extends AsyncTask<String, Void, String> {
            public void onPreExecute() {
                // Pbar.setVisibility(View.VISIBLE);
            }
            @Override
            protected String doInBackground(String... params) {

                InputStream inputStream = null;
                String result = null;
                try {

                    URL url = new URL("http://xxxxxxxxx/app/guard/guard_history.php");
                    JSONObject postDataParams = new JSONObject();
                    Log.e("Value>>>>>", String.valueOf(postDataParams));
                    postDataParams.put("guard_id", "1");
                    Log.e("params", postDataParams.toString());

                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                    conn.setReadTimeout(15000 /* milliseconds */);
                    conn.setConnectTimeout(15000 /* milliseconds */);
                    conn.setRequestMethod("POST");
                    conn.setDoInput(true);
                    conn.setDoOutput(true);
                    OutputStream os = conn.getOutputStream();
                    BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
                    writer.write(getPostDataString(postDataParams));

                    writer.flush();
                    writer.close();
                    os.close();

                    int responseCode=conn.getResponseCode();

                    if (responseCode == HttpsURLConnection.HTTP_OK) {

                        BufferedReader in=new BufferedReader(new InputStreamReader(conn.getInputStream()));
                        StringBuilder sb = new StringBuilder("");
                        String line="";
                        while ((line = in.readLine()) != null)
                        {
                            sb.append(line).append("\n");
                        }
                        result = sb.toString();
                    }

                    assert inputStream != null;
                    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8);
                    StringBuilder sb = new StringBuilder();

                    String line = null;
                    while ((line = reader.readLine()) != null)
                    {
                        sb.append(line).append("\n");
                    }
                    result = sb.toString();
                } catch (Exception e) {
                    Log.i("tagconvertstr", "["+result+"]");
                    System.out.println(e);
                }
                finally {
                    try{if(inputStream != null)inputStream.close();}catch(Exception squish){}
                }
                return result;
            }

            @Override
            protected void onPostExecute(String result){

                myJSON = result;
                prepareListData();

            }
        }
        GetDataJSON g = new GetDataJSON();
        g.execute();
    }



    public String getPostDataString(JSONObject params) throws Exception {

        StringBuilder result = new StringBuilder();
        boolean first = true;

        Iterator<String> itr = params.keys();

        while(itr.hasNext()){

            String key= itr.next();
            Object value = params.get(key);

            if (first)
                first = false;
            else
                result.append("&");

            result.append(URLEncoder.encode(key, "UTF-8"));
            result.append("=");
            result.append(URLEncoder.encode(value.toString(), "UTF-8"));

        }
        return result.toString();
    }


    private void prepareListData() {
        listDataHeader = new ArrayList<String>();
        listDataChild = new HashMap<String, List<String>>();
        List<String> top250 = new ArrayList<String>();

        try {
            peoples = new JSONArray(myJSON);
            for(int i=0;i<peoples.length();i++){
                JSONObject c = peoples.getJSONObject(i);

                company_name = c.getString("firm_name");
                from_date = c.getString("joining_date");
                to_date = c.getString("to_date");
                location=c.getString("duty_location");

                listDataHeader.add(company_name);
              //  System.out.println(company_name+" - "+from_date+" - "+to_date+" - "+location);
                top250.add("From Date: "+from_date);
                top250.add("To Date: "+to_date);
                top250.add("Location: "+location);
                listDataChild.put(listDataHeader.get(i), top250);

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




        // Adding child data
        //listDataHeader.add("Top 250");
        //listDataHeader.add("Now Showing");
      //  listDataHeader.add("Coming Soon..");

        // Adding child data
/*        top250.add("The Shawshank Redemption");
        top250.add("The Godfather");
        top250.add("The Godfather: Part II");
        top250.add("Pulp Fiction");
        top250.add("The Good, the Bad and the Ugly");
        top250.add("The Dark Knight");
        top250.add("12 Angry Men");

        List<String> nowShowing = new ArrayList<String>();
        nowShowing.add("The Conjuring");
        nowShowing.add("Despicable Me 2");
        nowShowing.add("Turbo");
        nowShowing.add("Grown Ups 2");
        nowShowing.add("Red 2");
        nowShowing.add("The Wolverine");

        List<String> comingSoon = new ArrayList<String>();
        comingSoon.add("2 Guns");
        comingSoon.add("The Smurfs 2");
        comingSoon.add("The Spectacular Now");
        comingSoon.add("The Canyons");
        comingSoon.add("Europa Report");*/




        listAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);

        // setting list adapter
        expListView.setAdapter(listAdapter);


    }
}  

和 ExpandableList 适配器

public class ExpandableListAdapter extends BaseExpandableListAdapter {

    private Context _context;
    private List<String> _listDataHeader; // header titles
    // child data in format of header title, child title
    private HashMap<String, List<String>> _listDataChild;

    public ExpandableListAdapter(Context context, List<String> listDataHeader,
                                 HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public View getChildView(int groupPosition, final int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {

        final String childText = (String) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_item, null);
        }

        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.lblListItem);

        txtListChild.setText(childText);
        return convertView;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this._listDataHeader.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return this._listDataHeader.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_group, null);
        }

        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.lblListHeader);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);

        return convertView;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

图片

Answer 1

检查您的代码后，更改您的 for 循环，例如: 对于(int i = 0;我

            company_name = c.getString("firm_name");
            from_date = c.getString("joining_date");
            to_date = c.getString("to_date");
            location=c.getString("duty_location");

            listDataHeader.add(company_name);
          //  System.out.println(company_name+" - "+from_date+" - "+to_date+" - "+location);
            top250.add("From Date: "+from_date);
            top250.add("To Date: "+to_date);
            top250.add("Location: "+location);
            listDataChild.put(listDataHeader.get(i), top250);
             top250 = new ArrayList<String>();

        }