Question

我正在尝试使用volley从URL获取数据一切正常（没有错误）但是我无法看到打开片段甚至进度对话的任何内容。你可以在这里找到引用：Custom List View我只想在片段中使用代码。提前致谢这是我的代码：

public class FragmentMain extends Fragment {
private static final String TAG = FragmentMain.class.getSimpleName();

// Movies json url
private static final String url = "http://api.example.com/json/movies.json";
private ProgressDialog pDialog;
private List<Movie> movieList = new ArrayList<>();
private CustomListAdapter adapter;
public FragmentMain() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    ListView listView = (ListView) getActivity().findViewById(R.id.list);
    adapter = new CustomListAdapter(getActivity(), movieList);
    listView.setAdapter(adapter);

    pDialog = new ProgressDialog(getActivity());
    // Showing progress dialog before making http request
    pDialog.setMessage("Loading...");
    pDialog.show();


    // Creating volley request obj
    JsonArrayRequest movieReq = new JsonArrayRequest(url,
            new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    Log.d(TAG, response.toString());
                    hidePDialog();

                    // Parsing json
                    for (int i = 0; i < response.length(); i++) {
                        try {

                            JSONObject obj = response.getJSONObject(i);
                            Movie movie = new Movie();
                            movie.setTitle(obj.getString("title"));
                            movie.setThumbnailUrl(obj.getString("image"));
                            movie.setRating(((Number) obj.get("rating"))
                                    .doubleValue());
                            movie.setYear(obj.getInt("releaseYear"));

                            // Genre is json array
                            JSONArray genreArry = obj.getJSONArray("genre");
                            ArrayList<String> genre = new ArrayList<>();
                            for (int j = 0; j < genreArry.length(); j++) {
                                genre.add((String) genreArry.get(j));
                            }
                            movie.setGenre(genre);

                            // adding movie to movies array
                            movieList.add(movie);

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

                    }

                    // notifying list adapter about data changes
                    // so that it renders the list view with updated data
                    adapter.notifyDataSetChanged();
                }
            }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d(TAG, "Error: " + error.getMessage());
            hidePDialog();

        }
    });

    // Adding request to request queue
    AppController.getInstance().addToRequestQueue(movieReq);

    // Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_main, container, false);
}

@Override
public void onDestroy() {
    super.onDestroy();
    hidePDialog();
}

private void hidePDialog() {
    if (pDialog != null) {
        pDialog.dismiss();
        pDialog = null;
    }
}

Answer 1

public class FragmentMain extends Fragment {
private static final String TAG = FragmentMain.class.getSimpleName();

private static final String url = "http://api.example.com/json/movies.json";
private ProgressDialog pDialog;
private List<Movie> movieList = new ArrayList<>();
private CustomListAdapter adapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
View view=inflater.inflate(R.layout.fragment_main, container, false);

ListView listView = (ListView) view.findViewById(R.id.list);
adapter = new CustomListAdapter(getActivity(), movieList);
listView.setAdapter(adapter);

pDialog = new ProgressDialog(getActivity());
// Showing progress dialog before making http request
pDialog.setMessage("Loading...");
pDialog.show();


// Creating volley request obj
JsonArrayRequest movieReq = new JsonArrayRequest(url,
        new Response.Listener<JSONArray>() {
            @Override
            public void onResponse(JSONArray response) {
                Log.d(TAG, response.toString());
                hidePDialog();

                // Parsing json
                for (int i = 0; i < response.length(); i++) {
                    try {

                        JSONObject obj = response.getJSONObject(i);
                        Movie movie = new Movie();
                        movie.setTitle(obj.getString("title"));
                        movie.setThumbnailUrl(obj.getString("image"));
                        movie.setRating(((Number) obj.get("rating"))
                                .doubleValue());
                        movie.setYear(obj.getInt("releaseYear"));

                        // Genre is json array
                        JSONArray genreArry = obj.getJSONArray("genre");
                        ArrayList<String> genre = new ArrayList<>();
                        for (int j = 0; j < genreArry.length(); j++) {
                            genre.add((String) genreArry.get(j));
                        }
                        movie.setGenre(genre);

                        // adding movie to movies array
                        movieList.add(movie);

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

                }

                // notifying list adapter about data changes
                // so that it renders the list view with updated data
                adapter.notifyDataSetChanged();
            }
        }, new Response.ErrorListener() {
    @Override
    public void onErrorResponse(VolleyError error) {
        VolleyLog.d(TAG, "Error: " + error.getMessage());
        hidePDialog();

    }
});

// Adding request to request queue
AppController.getInstance().addToRequestQueue(movieReq);

// Inflate the layout for this fragment
return view;

}

@Override
public void onDestroy() {
    super.onDestroy();
    hidePDialog();
}

private void hidePDialog() {
    if (pDialog != null) {
        pDialog.dismiss();
        pDialog = null;
    }
}

使用Fragment中的volley从JSON获取数据

1 个答案: