Question

我正在尝试做一个里面有listview的片段，我正在尝试使用JSON填充listview。我只有一个错误，我不知道在哪里发出单一错误。

错误指向getJSON（）;在返回的根视图下面说无效的方法声明

这是我扩展片段的代码，里面是listview

public class News extends Fragment {
    private ListView lv;
    private String JSON_STRING;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View rootView = inflater.inflate(news, container, false);
        lv = (ListView) rootView.findViewById(R.id.listView3);
        return rootView;
    }

    getJSON();


    private void showResult(){
        JSONObject jsonObject = null;
        ArrayList<HashMap<String,String>> list = new ArrayList<>();
        try {
            jsonObject = new JSONObject(JSON_STRING);
            JSONArray result = jsonObject.getJSONArray(Config.TAG_JSON_ARRAY1);

            for(int i = 0; i<result.length(); i++){
                JSONObject jo = result.getJSONObject(i);
                String NID = jo.getString(Config.TAG_NID);
                String title = jo.getString(Config.TAG_title);
                String content = jo.getString(Config.TAG_content);
                String n_date = jo.getString(Config.TAG_n_date);
                HashMap<String,String> match = new HashMap<>();
                match.put(Config.TAG_NID, NID);
                match.put(Config.TAG_title,title);
                match.put(Config.TAG_content,content);
                match.put(Config.TAG_n_date,n_date);
                list.add(match);
            }

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

        ListAdapter adapter = new SimpleAdapter(
                getActivity(), list, R.layout.newsadapterlayout,
                new String[]{Config.TAG_title,Config.TAG_content, Config.TAG_n_date, Config.TAG_NID},
                new int[]{ R.id.title, R.id.content, R.id.n_date});
        lv.setAdapter(adapter);
    }

    private void getJSON(){
        class GetJSON extends AsyncTask<Void,Void,String> {


            @Override
            protected void onPreExecute() {
                super.onPreExecute();

            }

            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                JSON_STRING = s;
                showResult();
            }

            @Override
            protected String doInBackground(Void... params) {
                RequestHandler rh = new RequestHandler();
                String s = rh.sendGetRequest(Config.URL_NEWS);
                return s;
            }
        }
        GetJSON gj = new GetJSON();
        gj.execute();
    }

非常感谢任何帮助。谢谢你们

Answer 1

您无法在方法内声明类。

将private void getJSON()与类GetJSON分开，只需将代码移到方法之外，您仍然可以执行; GetJSON gj = new GetJSON();

Android Fragment使用JSON填充listview

1 个答案: