Json数组在listview中没有正确显示

Question

输出：

我想在我的片段列表视图中显示我的Json数组。我创建了一个班级GetUser：

package com.gmakerorganisation.glocator.Fragments;

import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import com.android.volley.RequestQueue;
import com.gmakerorganisation.glocator.Config;
import com.gmakerorganisation.glocator.GetAllUsers;
import com.gmakerorganisation.glocator.R;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;


public class Sendrequest extends Fragment {
    private RequestQueue requestQueue;
    ArrayList<HashMap<String, String>> UserList;
    private static final String TAG_ID = "id";
    private static final String TAG_USERNAME = "username";
    private static final String TAG_NAME = "name";
    private static final String TAG_PHONE = "phone";
    private static final String TAG_PROFILE = "profile";
    GetAllUsers webreq = new GetAllUsers();
    ListView listView;
    public Sendrequest() {
        // Required empty public constructor
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v=inflater.inflate(R.layout.fragment_sendrequest, container, false);
        listView=(ListView)v.findViewById(R.id.list);
        new GetStudents().execute();

        return v;
    }

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

        // Hashmap for ListView

        ProgressDialog pDialog;

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


        }

        @Override
        protected Void doInBackground(Void... arg0) {
            // Creating service handler class instance
            GetAllUsers webreq = new GetAllUsers();

            // Making a request to url and getting response
            String jsonStr = webreq.makeWebServiceCall(Config.USERS_URL, GetAllUsers.GET);

            Log.d("Response: ", "> " + jsonStr);

            UserList = ParseJSON(jsonStr);

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            // Dismiss the progress dialog
            /**
             * Updating parsed JSON data into ListView
            li * */

             ListAdapter adapter = new SimpleAdapter(
                    getActivity().getApplicationContext(), UserList,
                    R.layout.list_item, new String[]{TAG_NAME, TAG_PHONE}, new int[]{R.id.name,
                    R.id.mobile});
            listView.setAdapter(adapter);
        }

    }

    private ArrayList<HashMap<String, String>> ParseJSON(String json) {
        if (json != null) {
            try {
                // Hashmap for ListView
                ArrayList<HashMap<String, String>> studentList = new ArrayList<HashMap<String, String>>();



                // Getting JSON Array node
                JSONArray userrs = new JSONArray(json);

                // looping through All Students
                for (int i = 0 ; i < userrs.length(); i++) {
                    JSONObject c = userrs.getJSONObject(i);

                    String id = c.getString(TAG_ID);
                    String username = c.getString(TAG_USERNAME);
                    String name = c.getString(TAG_NAME);
                    String phone = c.getString(TAG_PHONE);
                    String profile = c.getString(TAG_PROFILE);



                    // tmp hashmap for single student
                    HashMap<String, String> user = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    user.put(TAG_ID, id);
                    user.put(TAG_USERNAME, username);
                    user.put(TAG_NAME, name);
                    user.put(TAG_PHONE, phone);
                    user.put(TAG_PROFILE, profile);

                    // adding student to students list
                    studentList.add(user);
                }
                return studentList;
            } catch (JSONException e) {
                e.printStackTrace();
                return null;
            }
        } else {
            Log.e("ServiceHandler", "Couldn't get any data from the url");
            return null;
        }
    }
}

我在UserList中获取了正确的数据，所以我认为listview中存在问题。我的R.layout.list_item：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <!-- Name Label -->
    <TextView
        android:id="@+id/name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="2dip"
        android:paddingTop="6dip"
        android:text="Name"
        android:textSize="16sp"
        android:textStyle="bold" />


    <!-- Mobile number label -->
    <TextView
        android:id="@+id/mobile"
        android:layout_width="220dp"
        android:layout_height="wrap_content"
        android:gravity="left"
        android:text="Phone: " />

</LinearLayout>

我的json是这样的：

[{"id":"1","username":"gmaker","name":"SHUBHAM SHARMA","phone":"9711979977","profile":"http:\/\/glocator.esy.es\/profilepicture\/1."},{"id":"4","username":"somnath","name":"","phone":"9582223881","profile":""},{"id":"7","username":"shitij","name":"","phone":"9650154839","profile":""}]           

Answer 1

更新列表时使用mAdapter.notifyDataSetChanged()来更新适配器：

UserList = ParseJSON(jsonStr);
mAdapter.notifyDataSetChanged();

随着你的适配器初始化：

mAdapter = new SimpleAdapter(
                    getActivity().getApplicationContext(), UserList,
                    R.layout.list_item, new String[]{TAG_NAME, TAG_PHONE}, new int[]{R.id.name,
                    R.id.mobile});
listView.setAdapter(adapter);