java - 如何在 Android 中对组和子级可扩展 ListView 进行排序？

Question

我在 mysql 中有两个表，它们通过 ID“id_catprods”和“ID_Cat”绑定(bind)“类别”和“产品”。到目前为止一切顺利，我正在使用带有自定义适配器的“ExpandableListView”在 Android 上工作，一切正常，但找不到用他们的产品对类别进行排序的解决方案。谁能帮帮我？

Json 结果:

{
"productos": [{
    "id_catprods": "1",
    "id_oferta": "197",
    "id_producto": "1",
    "nombr_cat": "Bocatas",
    "id_cat": "1",
    "nombre_producto": "Lomo",
    "precio": "4",
    "actions": []
}, {
    "id_catprods": "2",
    "id_oferta": "197",
    "id_producto": "2",
    "nombr_cat": "Pizzas",
    "id_cat": "2",
    "nombre_producto": "Serranito",
    "precio": "4",
    "actions": []
}],
"errorCode": 0,
"errorString": "Todo correcto"
}

主要代码:

// DownloadJSON AsyncTask
        private class DownloadJSON extends AsyncTask<Void, Void, Void> {
            String givemeurl;

            public DownloadJSON(String url) {
                this.givemeurl = id_oferta;
            }


            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                mProgressDialog = new ProgressDialog(Category.this);
                mProgressDialog.setMessage("Cargando...");
                mProgressDialog.setIndeterminate(false);
                mProgressDialog.show();
            }

            @Override
            protected Void doInBackground(Void... params) {
                // Create an array
                arraylist = new ArrayList<HashMap<String, String>>();
                // Retrieve JSON Objects from the given URL address
                jsonobject = JSONfunctions
                        .getJSONfromURL("http://file.php");

                if(jsonobject != null){         
                    try {
                        // Locate the array name in JSON
                        jsonarray = jsonobject.getJSONArray("productos");

                        for (int i = 0; i < jsonarray.length(); i++) {
                            HashMap<String, String> map = new HashMap<String, String>();
                            jsonobject = jsonarray.getJSONObject(i);
                            // Retrive JSON Objects
                            map.put("nombr_cat", jsonobject.getString("nombr_cat"));
                            map.put("nombre_producto", jsonobject.getString("nombre_producto"));
                            map.put("id_cat", jsonobject.getString("id_cat"));
                            arraylist.add(map);
                        }

                    } catch (JSONException e) {
                        Log.e("Error", e.getMessage());
                        //e.printStackTrace();
                    } catch (Exception e) {
                        Log.e("Error", e.getMessage());         
                    }
                }else{
                    //Log.e("Response","No data");
                }

                return null;
            }

            @Override
            protected void onPostExecute(Void args) {
                ExpandableListView = (ExpandableListView) findViewById(R.id.expandableListView1);

                /*if(listview.getCount() == 0){
                    listview.setVisibility(View.GONE); // ERROR A CORREGIR, DOBLE CAPA?
                    listview.setEmptyView(findViewById(givemeempty));
                    TextView bottom = new TextView(Category.this);
                    bottom.setHeight(50); //50dp
                    bottom.setText("");
                    // Adding bottom
                    listview.addFooterView(bottom);
                }else{
                }*/
                adapter = new ListViewAdapterCat(Category.this, arraylist);
                ExpandableListView.setAdapter(adapter);
                mProgressDialog.dismiss();
            }
        }

适配器代码:

 public class ListViewAdapterCat extends BaseExpandableListAdapter {

    Context context;
    ArrayList<HashMap<String, String>> data;
    //ImageLoader imageLoader;
    HashMap<String, String> resultp = new HashMap<String, String>();

    public ListViewAdapterCat(Context context,
            ArrayList<HashMap<String, String>> arraylist) {
        this.context = context;
        data = arraylist;    
        //imageLoader = new ImageLoader(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 arg0, int arg1, boolean arg2, View arg3,
            ViewGroup arg4) {   
        TextView tv = null;
        for (int i = 0; i < data.size(); i++) {
            tv = new TextView(context);
            tv.setTextSize(20);
            tv.setPadding(50, 0, 0, 0);
            System.out.println(data.get(i).get("id_cat"));
            if(data.get(i).get("id_cat").equals("1")){
                tv.setText(resultp.get(Category.nombre_producto));
            }else if (data.get(i).get("id_cat").equals("2")){
                tv.setText(resultp.get(Category.nombre_producto));
            }else if (data.get(i).get("id_cat").equals("3")){
                tv.setText(resultp.get(Category.nombre_producto));
            }

        }
        return tv;
    }
    @Override
    public int getChildrenCount(int arg0) {
        // TODO Auto-generated method stub
        return 1;
    }
    @Override
    public Object getGroup(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }
    @Override
    public int getGroupCount() {
        // TODO Auto-generated method stub
        return data.size();
    }
    @Override
    public long getGroupId(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }
    @Override
    public View getGroupView(int arg3, boolean arg1, View convertView, ViewGroup arg4) {

        ViewHolder holder;
        if(convertView == null){

            LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.category_item, null);

            holder = new ViewHolder();

            holder.nombr_cat = (TextView) convertView.findViewById(R.id.nombree);
            Log.e("ID DEL GRUPO", ""+arg3);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }

        resultp = data.get(arg3);

        holder.nombr_cat.setText(resultp.get(Category.nombr_cat));
        holder.nombr_cat.setTextSize(20);
        return convertView;
    }
    @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;
    }
    private static class ViewHolder {
        public TextView nombr_cat;
        public TextView nombre_producto;
    }
}

Answer 1

如果可能，在 MySql 中查询时对它们进行排序。否则，这是一个建议。将类别存储在 ArrayList<String> 中.您可以使用 Collection.sort() 之一轻松对它们进行排序.然后，将您的产品存储在 Hashtable<String, ArrayList<Product>> 中其中键是类别名称，数据是存储产品详细信息的产品类。您可以使用 Comparator<Product> 对产品类别进行排序.您将需要相应地修改适配器。