解析json后无法在RecyclerView上显示int或double

Question

当我只显示字符串数据时，它似乎显示正常，但是当我尝试显示 int 或 double 时，RecyclerView 不会填充。我从 Google 地方 API JSON 中提取。我想也许这就是我使用我的onBindViewHolder()? 谢谢// MainActivityprivate void getJson() {    String URL = https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=40.7085,-74.003124&opennow&radius=5000&type=restaurant&key=    JsonObjectRequest root = new JsonObjectRequest(Request.Method.GET, URL, null, new Response.Listener<JSONObject>() {        @Override        public void onResponse(JSONObject response) {            try {                JSONArray results = response.getJSONArray("results");                Log.d("RESULTS", String.valueOf(results));                for(int i = 0; i<results.length(); i++) {                    JSONObject resultsObj = results.getJSONObject(i);                    mImageUrls.add(resultsObj.getString("icon"));                    mTitle.add(resultsObj.getString("name"));                    //mRating.add(resultsObj.getDouble("rating"));                    mPriceLevel.add(resultsObj.getInt("price_level"));                }                getRecyclerView();            } catch (JSONException e) {                e.printStackTrace();            }        }    },new Response.ErrorListener() {        @Override        public void onErrorResponse(VolleyError error) {        }    });    mRequestQueue.add(root);}private void getRecyclerView() {    // LinearLayoutManager    recyclerView = findViewById(R.id.recyclerView);    adapter = new RecyclerViewAdapter(mImageUrls, mTitle, mPriceLevel, this);    recyclerView.setAdapter(adapter);    recyclerView.setLayoutManager(new LinearLayoutManager(this));    recyclerView.setHasFixedSize(true);}而RecyclerViewAdapter班级是。

Answer 1

这样做的原因是您没有将 Double 转换为 String 将此行更改holder.rating.setText(rRatings.get(position));为holder.rating.setText(String.valueOf(rRatings.get(position)));

Answer 2

首先，您应该检查您获得的评级是否为双倍值。可能是在这一行之后抛出异常

mRating.add(resultsObj.getDouble("rating"))

同样，@hooray_todd siggested textview 只采用字符串值，因此您必须将数据更改为字符串。

Answer 3

我建议您创建一个包含所有必要参数的对象，然后将该对象的单个列表传递给RecyclerViewAdapter.

public class MapElement {

    public String name;

    public String imageUrl;

    public Double rating;

    public Integer price;

}

然后ArrayList在您从getJson函数调用中获得响应时创建此对象的一个。现在在您的适配器中只需使用单个MapElement对象列表来显示那里的数据。

修改后的适配器应如下所示。

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>{

    private static final String TAG = "RecyclerViewAdapter";

    private ArrayList<MapElement> elements = new ArrayList<>();

    private Context mContext;

    public RecyclerViewAdapter(ArrayList<MapElement> elements, Context context) {

        this.elements = elements;

        mContext = context;

    }

    @NonNull

    @Override

    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_item, parent, false);

        ViewHolder holder = new ViewHolder(view);

        return holder;

    }

    @Override

    public void onBindViewHolder(@NonNull ViewHolder holder, final int position) {

        Glide.with(mContext).asBitmap().load(rImageUrls.get(position)).into(holder.image);

        holder.name.setText(elements.get(position).name);

        holder.rating.setText(elements.get(position).rating);

        holder.priceLevel.setText(elements.get(position).price);

        holder.parentLayout.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                Log.d(TAG, "onClick: clicked on an image: " + rNames.get(position));

                Toast.makeText(mContext, elements.get(position).name, Toast.LENGTH_SHORT).show();

            }

        });

    }

    @Override

    public int getItemCount() {

        return elements.size();

    }

    public class ViewHolder extends RecyclerView.ViewHolder{

        ImageView image;

        TextView name;

        TextView rating;

        TextView priceLevel;

        TextView address;

        RelativeLayout parentLayout;

        public ViewHolder(View itemView) {

            super(itemView);

            image = (ImageView) itemView.findViewById(R.id.image);

            name = (TextView) itemView.findViewById(R.id.title);

            rating = itemView.findViewById(R.id.rating);

            priceLevel = (TextView) itemView.findViewById(R.id.priceLevel);

            parentLayout = itemView.findViewById(R.id.parentLayout);

        }

    }

}