如何用Android的listview项对listview进行排序？

Question

我有一个从数据库填充的列表视图。该列表显示了具有以下详细信息的可用食物：

1. 准备食物的时间
2. 餐厅等级
3. 餐厅的长/长
4. 食物的数量。

现在，我要基于这四个项目对列表视图进行排序。我正在使用ArrayList<HashMap<String, String>>和扩展baseadapter的适配器。

我在Collections.sort上看到了很多答案，但是我无法在代码中实现它。

NOTE：我没有为AvailableFood对象定义数据模型来填充arrayList。这是我的代码：

AvailableFood.java

public class AvailableFood extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        rootview = inflater.inflate(R.layout.fragment_available_food, container, false);

        mBottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
                switch (menuItem.getItemId()){
                    case R.id.nav_sort:
                        PopupMenu popup = new PopupMenu(getContext(), rootview.findViewById(R.id.nav_sort));
                        MenuInflater inflater = popup.getMenuInflater();
                        inflater.inflate(R.menu.sort_menu, popup.getMenu());
                        popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                            @Override
                            public boolean onMenuItemClick(MenuItem menuItem) {
                                switch (menuItem.getItemId()){
                                    case R.id.sort_recent: sortAvailableFood("Time");
                                        break;
                                    case R.id.sort_qty: sortAvailableFood("Qty");
                                        break;
                                    case R.id.sort_rating: sortAvailableFood("Rating");
                                        break;
                                    case R.id.sort_distance: sortAvailableFood("Distance");
                                        break;
                                }
                                return true;
                            }
                        });
                        popup.show();

                }
                return false;
            }

        });
        lvAvlFood = rootview.findViewById(R.id.list_avl_food);

        arrListAvlFood = new ArrayList<HashMap<String, String >>();
        arrListLoc = new ArrayList<HashMap<String, String>>();

        return rootview;
    }

    private void sortAvailableFood(String by) {
        switch (by){
            case"Time":
                Collections.sort(arrListAvlFood, new Comparator<HashMap<String, String>>() {
                    @Override
                    public int compare(HashMap<String, String> obj1, HashMap<String, String> obj2) {
                        return 1;
                    }
                });
                break;
            case"Qty":
                break;
            case"Rating":
                break;
            case"Distance":
                break;
        }
    }

    private class LoadAllFood extends AsyncTask<String, String, String>{

        @Override
        protected String doInBackground(String... strings) {
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            String ngoId = new SessionManager(getContext()).getUserId();
            if(ngoId != null || !ngoId.equals("")) {
                params.add(new BasicNameValuePair("n_id", ngoId));
            }
            JSONObject json = jParser.makeHttpRequest(url_avl_food, "GET", params);

            try {
                int success = json.getInt("success");

                if (success == 1) {

                    jaAvlFood = json.getJSONArray("avl_food");

                    // looping through All Food
                    for (int i = 0; i < jaAvlFood.length(); i++) {
                        JSONObject c = jaAvlFood.getJSONObject(i);


                        String prep_time = c.getString("prep_time");
                        String upload_time = c.getString("upload_time");
                        Double qty = c.getDouble("qty");
                        resName = c.getString("res_name");
                        String lat = c.getString("lat");
                        String longi = c.getString("longi");
                        String rating = c.getString("g_rating");

                        HashMap<String, String> map = new HashMap<String, String>();
                        HashMap<String, String> hmLatLong = new HashMap<String, String>();

                        map.put("f_id", f_id);


                        map.put("prep_time",prep_time);
                        map.put("upload_time",upload_time);
                        map.put("qty",qty.toString());
                        map.put("name",resName);
                        map.put("g_rating", rating);


                        hmLatLong.put("lat",lat);
                        hmLatLong.put("longi",longi);

                        arrListAvlFood.add(map);
                        arrListLoc.add(hmLatLong);
                    }
                } else {

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

    }



}

Answer 1

我认为您需要在对列表进行排序后更新适配器，您正在这样做吗？