2

My RecyclerView in Fragment (FrameLayout) is sometimes empty on BottomNavigationView item touch (sometimes you can touch 5x and it's not empty but then it's empty again until the next touch).

YouTuberFragment

public class YouTuberFragment extends Fragment {

    private List<YouTuber> youtuber;

    private class GetYouTuber extends AsyncTask<Void, Void, Void> {

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

        @Override
        protected Void doInBackground(Void... arg0) {
            try {
                InputStream inputStream = getActivity().getAssets().open("youtuber.json");
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                StringBuilder total = new StringBuilder();
                String line;

                while ((line = bufferedReader.readLine()) != null) total.append(line);

                String m = total.toString();
                JSONObject jsonObject = new JSONObject(m);
                JSONArray jsonYouTuberArray = jsonObject.getJSONArray("youtuber");

                int youTubersCount = 0;
                if (jsonYouTuberArray != null) youTubersCount = jsonYouTuberArray.length();

                for (int i = 0; i < youTubersCount; i++) {
                    JSONObject jsonYouTuberObject = jsonYouTuberArray.getJSONObject(i);

                    YouTuber youTuber = new YouTuber(
                            jsonYouTuberObject.getString("name"),
                            jsonYouTuberObject.getString("role"),
                            jsonYouTuberObject.getString("picture"),
                            jsonYouTuberObject.getString("episodes"),
                            jsonYouTuberObject.getString("youtube")
                    );

                    youtuber.add(youTuber);
                }
            } catch (JSONException | IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
        }
    }

    public YouTuberFragment() {

    }

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

        LinearLayoutManager llm = new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false);
        youtuber = new ArrayList<>();
        RVAdapter adapter = new RVAdapter(youtuber, getContext());

        new YouTuberFragment.GetYouTuber().execute();

        RecyclerView rv = (RecyclerView) v.findViewById(R.id.rv);
        rv.setLayoutManager(llm);
        rv.setHasFixedSize(true);
        rv.setAdapter(adapter);

        return v;
    }

}

RVAdapter

class RVAdapter extends RecyclerView.Adapter<RVAdapter.PersonViewHolder> {

    private final Context context;
    private Resources res;
    private List<YouTuber> youTuber;
    RVAdapter(List<YouTuber> youTuber, Context context){
        this.youTuber = youTuber;
        this.context = context;
    }

    static class PersonViewHolder extends RecyclerView.ViewHolder {
        CardView cv;
        ImageView ytPicture;
        TextView ytName;
        TextView ytRole;
        TextView ytEpisodes;
        Button ytYoutube;

        PersonViewHolder(View itemView) {
            super(itemView);

            cv = (CardView) itemView.findViewById(R.id.cv);
            ytPicture = (ImageView) itemView.findViewById(R.id.yt_picture);
            ytName = (TextView) itemView.findViewById(R.id.yt_name);
            ytRole = (TextView) itemView.findViewById(R.id.yt_role);
            ytEpisodes = (TextView) itemView.findViewById(R.id.yt_episodes);
            ytYoutube = (Button) itemView.findViewById(R.id.yt_youtube);
        }
    }

    @Override
    public void onAttachedToRecyclerView(RecyclerView recyclerView) {
        super.onAttachedToRecyclerView(recyclerView);
    }

    @Override
    public PersonViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_youtuber, viewGroup, false);
        res = v.getResources();
        PersonViewHolder pvh = new PersonViewHolder(v);
        return pvh;
    }

    @Override
    public void onBindViewHolder(final PersonViewHolder personViewHolder, final int i) {
        personViewHolder.ytPicture.setImageResource(res.getIdentifier(youTuber.get(i).picture, "drawable", BuildConfig.APPLICATION_ID));
        personViewHolder.ytName.setText(youTuber.get(i).name);
        personViewHolder.ytRole.setText(youTuber.get(i).role);
        personViewHolder.ytEpisodes.setText(res.getString(R.string.yt_episodes, youTuber.get(i).episodes));
        personViewHolder.ytYoutube.setText(youTuber.get(i).youtube);

        personViewHolder.ytYoutube.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Uri uri = Uri.parse("https://" + youTuber.get(i).youtube);

                Intent youtube_url = new Intent(Intent.ACTION_VIEW, uri);
                context.startActivity(youtube_url);
            }
        });
    }

    @Override
    public int getItemCount() {
        return youTuber.size();
    }
}
4

1 回答 1

3

可能是您正在运行不同的线程来收集数据，而适配器初始化正在主线程上运行，并且在检索数据之前正在呈现。如果设备为空白，您是否尝试过旋转设备？

于 2017-06-04T01:55:01.893 回答