Question

我正在使用Gson和Json来保存用于显示包含图像和文本的帖子的对象。问题是保存的帖子不会显示在listView中。我成功保存了帖子但没有加载它们。

PlaceViewFragment中的

- 应该显示帖子

     @Override
public void onStop() {
    super.onStop();
    SharedPreferences prefs = activity.getSharedPreferences(desination, 0);

    SharedPreferences.Editor prefsEditor = prefs.edit();
    Gson gson = new Gson();
    String json = gson.toJson(contentList);

    prefsEditor.putString(desination, json);

    prefsEditor.commit();
}



         @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_place_view, container, false);
        activity = this.getActivity();

        desination = getArguments().getString("destination");

        /**
         *Load contentItems using Json.
         **/
        SharedPreferences prefs = activity.getSharedPreferences(desination, 0);
/*
        SharedPreferences.Editor prefsEditor = prefs.edit();
        prefsEditor.clear();
        prefsEditor.commit();
*/

        Gson gson = new Gson();
        String json = prefs.getString(desination, null);

        Map<String, ?> keys = prefs.getAll();

        for (Map.Entry<String, ?> entry : keys.entrySet()) {
            Log.d("map values", entry.getKey() + ": " +
                    entry.getValue().toString());
        }

        Type type = new TypeToken<ArrayList<ContentItem>>() {
        }.getType();
        contentList = gson.fromJson(json, type);
        // Log.d("Contentlist 1", contentList.get(0).getImages().get(0).toString());
        if (contentList == null) {
            contentList = new ArrayList<ContentItem>();
        }


        listView = (ListView) view.findViewById(R.id.listView2);

        // get data from the table by the ListAdapter

        listView.setAdapter(myAdapter);
        myAdapter = new MyAdapter(this.getActivity(), R.layout.view_layout, contentList);

MyAdapter

  @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public ContentItem getItem(int position) {
        return items.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        View v = convertView;
        ViewHolder holder;

        if (v == null) {

            v = mInflater.inflate(R.layout.view_layout, parent, false);
            holder = new ViewHolder();
            holder.date = (TextView) v.findViewById(R.id.dateview);
            holder.cap = (TextView) v.findViewById(R.id.caption);
            holder.tt1 = (TextView) v.findViewById(R.id.textview1);
            holder.tt2 = (TextView) v.findViewById(R.id.textview2);
            holder.tt3 = (TextView) v.findViewById(R.id.textview3);
            holder.im1 = (ImageView) v.findViewById(R.id.image1);
            holder.im2 = (ImageView) v.findViewById(R.id.image2);
            holder.im3 = (ImageView) v.findViewById(R.id.image3);

            v.setTag(holder);
        } else {
            v = convertView;
            holder = (ViewHolder) v.getTag();
        }

        ContentItem p = getItem(position);



        holder.date.setText(p.getDate());
        holder.cap.setText(p.getCaption());

        if (p.getTexts().size() > 0) {
            holder.tt1.setText(p.getTexts().get(0));
            holder.tt1.setVisibility(View.VISIBLE);


            holder.tt2.setText(p.getTexts().get(1));
            holder.tt2.setVisibility(View.VISIBLE);


            holder.tt3.setText(p.getTexts().get(2));
            holder.tt3.setVisibility(View.VISIBLE);
        }

        if (p.getImages().size() > 0) {
            holder.im1.setImageBitmap(loadImageFromStorage(p.getImages().get(0)));
            holder.im1.setVisibility(View.VISIBLE);

            holder.im2.setImageBitmap(loadImageFromStorage(p.getImages().get(1)));
            holder.im2.setVisibility(View.VISIBLE);

            holder.im3.setImageBitmap(loadImageFromStorage(p.getImages().get(2)));
            holder.im3.setVisibility(View.VISIBLE);
        }


        return v;
    }

    private class ViewHolder {
        public ImageView im1, im2, im3;
        public TextView date, cap, tt1, tt2, tt3;
    }

    private Bitmap loadImageFromStorage(String path) {
        Bitmap b = null;
        try {
            File f = new File(path, "image.jpg");
            b = BitmapFactory.decodeStream(new FileInputStream(f));


        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        return b;
    }

}

我认为这个代码出了问题。

Answer 1

你反转了方法调用，你有

listView.setAdapter(myAdapter);
myAdapter = new MyAdapter(this.getActivity(), R.layout.view_layout, contentList);

应该是

myAdapter = new MyAdapter(this.getActivity(), R.layout.view_layout, contentList);
listView.setAdapter(myAdapter);

我的listView项目不会显示

1 个答案: