android - RecyclerView 不显示项目

问题描述

我创建了一个应用程序，它在放置在片段中的 RecyclerView 中显示食品订单。使用 AsyncTask 检索食品订单详细信息。但不知何故，片段中没有显示任何内容。它保持空白。我一定是忘记了什么或忽略了什么。

这是订单片段：

public class OrdersFragment extends Fragment {
RecyclerView recyclerView;
private OrdersAdapter adapter;
RecyclerView.LayoutManager layoutManager;
private static List<Orders> orderslist;



 public static final MediaType JSON = MediaType.parse("application/json; 
charset=utf-8");

SharedPreferences sharedPreferences;
View view;

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

    sharedPreferences = getActivity().getSharedPreferences("UserInfo",0);
    view = inflater.inflate(R.layout.fragment_orders, container, false);

    recyclerView = (RecyclerView) view.findViewById(R.id.recycler_view);
    orderslist = new ArrayList<>();

    new load_orders().execute();


    return view;
}




   public class load_orders extends AsyncTask<String, Void, Void>  {
        @Override
        protected Void doInBackground(String... strings) {
            try{
                OkHttpClient client = new OkHttpClient();
                JSONObject json = new JSONObject();
                JSONObject datajson = new JSONObject();
                datajson.put("command","ecoexpress_orders");
                datajson.put("username", 
sharedPreferences.getString("Username",null));
                json.put("data",datajson);

                RequestBody body = RequestBody.create(JSON, 
json.toString());

                Request request = new Request.Builder()
                        .url("https://api.watext.com/hook/insert_pagetoken")
                        .post(body)
                        .addHeader("content-type", "application/json")
                        .addHeader("cache-control", "no-cache")
                        .addHeader("postman-token", "55747e8a-0a9a-1fd5-77b0-8af0027be1f1")
                        .build();
                Response response = client.newCall(request).execute();

                JSONObject responseJSON = new JSONObject(response.body().string());
                JSONArray messageArray = responseJSON.getJSONArray("message");



                for (int i = 0; i < messageArray.length(); i ++ ){


                    JSONObject order_item = messageArray.getJSONObject(i);
                    Orders orders = new Orders(order_item.getString("order_id"),
                            order_item.getString("order_details"));

                    orderslist.add(orders);

                }

            }
            catch (Exception e){


                return null;
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {

            layoutManager = new LinearLayoutManager(getActivity());

            adapter = new OrdersAdapter(getContext(),orderslist);

            recyclerView.setLayoutManager(layoutManager);
            recyclerView.setAdapter(adapter);
        //adapter.notifyDataSetChanged();
        }
    }



}

这是模型 Order.class：

public class Orders {


        private String order_id;
        private String order_details;

        public Orders(String order_id, String order_details) {
            this.order_id = order_id;
            this.order_details = order_details;
        }

        public String getOrder_id() {
            return order_id;
        }

        public void setOrder_id(String order_id) {
            this.order_id = order_id;
        }

        public String getOrder_details() {
            return order_details;
        }

        public void setOrder_details(String order_details) {
            this.order_details = order_details;
        }

}

这是 OrdersAdapter：

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

    private Context ctx;
    private List<Orders> list;


    public OrdersAdapter(Context ctx, List<Orders> list) {
        this.ctx = ctx;
        this.list = list;
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.cards_layout, viewGroup, false);

        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int i) {

       viewHolder.id.setText(list.get(i).getOrder_id());
        viewHolder.details.setText(list.get(i).getOrder_details());

    }

    @Override
    public int getItemCount() {

        return list.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder{

        public TextView id, details;

        public ViewHolder( View itemView) {
            super(itemView);

            id = (TextView)itemView.findViewById(R.id.orderID_textview);
            details = (TextView)itemView.findViewById(R.id.orderDetails_textview);

        }
    }
}

这是 OrdersFragment 的布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">


       <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scrollbars="vertical"

            />



</RelativeLayout>

CardView 的布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
   >

    <android.support.v7.widget.CardView
        android:id="@+id/card_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center"
        card_view:cardBackgroundColor="@color/colorPrimary"
        card_view:cardCornerRadius="10dp"
        card_view:cardElevation="5dp"
        card_view:cardUseCompatPadding="true">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            >



            <LinearLayout
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginTop="12dp"
                android:layout_weight="2"
                android:orientation="vertical"
                >

                <TextView
                    android:id="@+id/orderID_textview"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_horizontal"
                    android:layout_marginTop="10dp"
                    android:text="Order ID"
                   />

                <TextView
                    android:id="@+id/orderDetails_textview"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_horizontal"
                    android:layout_marginTop="10dp"

                    android:text="Order Details"
                   />

            </LinearLayout>
        </LinearLayout>

    </android.support.v7.widget.CardView>

</LinearLayout>

提前致谢！

标签： androidandroid-recyclerviewandroid-asynctask

android - RecyclerView 不显示项目

问题描述

解决方案

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