如何在android listview中訪問JSON對象的值？

Question

我想訪問列表視圖中的「地址」對象內的「區域」值。請參閱json的圖像。

我想解析列表視圖中的json數據，但我無法訪問地址內的區域。在使用此代碼後，我得到空值。

看到的圖像我越來越區域爲空。

我怎樣才能獲得區域？

listrow.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:background="@drawable/list_row_selector" 
    android:padding="8dp" > 

    <!-- Thumbnail Image --> 
    <com.android.volley.toolbox.NetworkImageView 
     android:id="@+id/thumbnail" 
     android:layout_width="120dp" 
     android:layout_height="80dp" 
     android:layout_alignParentLeft="true" 
     android:layout_marginRight="8dp" /> 

    <!-- Restaurant name --> 
    <TextView 
     android:id="@+id/name" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 

     android:layout_toRightOf="@+id/thumbnail" 
     android:textSize="@dimen/title" 
     android:textStyle="bold" /> 

    <TextView 
     android:id="@+id/area" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@id/name" 

     android:layout_toRightOf="@+id/thumbnail" 
     android:textSize="@dimen/rating" /> 

    <!-- Rating --> 
    <TextView 
     android:id="@+id/average_ratings" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@id/area" 
     android:layout_toRightOf="@+id/thumbnail" 

     android:textSize="@dimen/rating" /> 

    <TextView 
     android:id="@+id/cuisine" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@id/average_ratings" 

     android:layout_toRightOf="@+id/thumbnail" 
     android:textSize="@dimen/rating" /> 

    <!-- Genre --> 
    <!-- <TextView 
     android:id="@+id/genre" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" 
     android:layout_below="@id/rating" 
     android:layout_marginTop="5dp" 
     android:layout_toRightOf="@+id/thumbnail" 
     android:textColor="@color/genre" 
     android:textSize="@dimen/genre" />--> 
<!-- 
    &lt;!&ndash; Release Year &ndash;&gt; 
    <TextView 
     android:id="@+id/releaseYear" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentBottom="true" 
     android:layout_alignParentRight="true" 
     android:textColor="@color/year" 
     android:textSize="@dimen/year" />--> 

</RelativeLayout> 

主要活動

public class MainActivity extends Activity { 
    // Log tag 
    private static final String TAG = MainActivity.class.getSimpleName(); 
    private static final String url = "http://sewqusviwc.localtunnel.me/api/v1/restaurants?per_page=10&page=1&sort_col=average_ratings"; 
    // Movies json url 
    //private static final String url = "http://api.androidhive.info/json/movies.json"; 
    private ProgressDialog pDialog; 
    private List<Movie> movieList = new ArrayList<Movie>(); 
    private ListView listView; 
    private CustomListAdapter adapter; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     listView = (ListView) findViewById(R.id.list); 
     adapter = new CustomListAdapter(this, movieList); 
     listView.setAdapter(adapter); 

     pDialog = new ProgressDialog(this); 
     // Showing progress dialog before making http request 
     pDialog.setMessage("Loading..."); 
     pDialog.show(); 

     // changing action bar color 
     getActionBar().setBackgroundDrawable(
       new ColorDrawable(Color.parseColor("#1b1b1b"))); 

     // Creating volley request obj 
     JsonArrayRequest movieReq = new JsonArrayRequest(url, 
       new Response.Listener<JSONArray>() { 
        @Override 
        public void onResponse(JSONArray response) { 
         Log.d(TAG, response.toString()); 
         hidePDialog(); 

         // Parsing json 
         for (int i = 0; i < response.length(); i++) { 
          try { 

           JSONObject obj = response.getJSONObject(i); 
           Movie movie = new Movie(); 
           //movie.setTitle(obj.getString("title")); 
           movie.setName(obj.getString("name")); 
           //movie.setThumbnailUrl(obj.getString("image")); 
           movie.setThumbnailUrl(obj.getString("image_url")); 
           movie.setAverage_ratings(obj.getString("average_ratings")); 
           movie.setCuisine(obj.getString("cuisine")); 
           //movie.setYear(obj.getInt("releaseYear")); 

           // Genre is json array 
           /*JSONArray genreArry = obj.getJSONArray("genre"); 
           ArrayList<String> genre = new ArrayList<String>(); 
           for (int j = 0; j < genreArry.length(); j++) { 
            genre.add((String) genreArry.get(j)); 
           } 
           movie.setGenre(genre);*/ 

           // adding movie to movies array 
           movieList.add(movie); 

          } catch (JSONException e) { 
           e.printStackTrace(); 
          } 

         } 

         // notifying list adapter about data changes 
         // so that it renders the list view with updated data 
         adapter.notifyDataSetChanged(); 
        } 
       }, new Response.ErrorListener() { 
        @Override 
        public void onErrorResponse(VolleyError error) { 
         VolleyLog.d(TAG, "Error: " + error.getMessage()); 
         hidePDialog(); 

        } 
       }); 

     // Adding request to request queue 
     AppController.getInstance().addToRequestQueue(movieReq); 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     hidePDialog(); 
    } 

    private void hidePDialog() { 
     if (pDialog != null) { 
      pDialog.dismiss(); 
      pDialog = null; 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.main, menu); 
     return true; 
    } 

} 

自定義列表適配器

public class CustomListAdapter extends BaseAdapter { 
    private Activity activity; 
    private LayoutInflater inflater; 
    private List<Movie> movieItems; 
    ImageLoader imageLoader = AppController.getInstance().getImageLoader(); 

    public CustomListAdapter(Activity activity, List<Movie> movieItems) { 
     this.activity = activity; 
     this.movieItems = movieItems; 
    } 

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

    @Override 
    public Object getItem(int location) { 
     return movieItems.get(location); 
    } 

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

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

     if (inflater == null) 
      inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     if (convertView == null) 
      convertView = inflater.inflate(R.layout.list_row, null); 

     if (imageLoader == null) 
      imageLoader = AppController.getInstance().getImageLoader(); 
     NetworkImageView thumbNail = (NetworkImageView) convertView 
       .findViewById(R.id.thumbnail); 
     TextView name = (TextView) convertView.findViewById(R.id.name); 
     TextView average_ratings = (TextView) convertView.findViewById(R.id.average_ratings); 
     TextView address=(TextView) convertView.findViewById(R.id.area); 
     TextView cuisine =(TextView) convertView.findViewById(R.id.cuisine); 
     //TextView genre = (TextView) convertView.findViewById(R.id.genre); 
     //TextView year = (TextView) convertView.findViewById(R.id.releaseYear); 

     // getting movie data for the row 
     Movie m = movieItems.get(position); 

     // thumbnail image 
     thumbNail.setImageUrl(m.getThumbnailUrl(), imageLoader); 

     // title 
     name.setText(m.getName()); 

     // rating 
     average_ratings.setText("Rating: " + String.valueOf(m.getAverage_ratings())); 
     address.setText("Area: " + String.valueOf(m.getAddress())); 
     cuisine.setText("Cusine: " + String.valueOf(m.getCuisine())); 
     /*// genre 
     String genreStr = ""; 
     for (String str : m.getGenre()) { 
      genreStr += str + ", "; 
     } 
     genreStr = genreStr.length() > 0 ? genreStr.substring(0, 
       genreStr.length() - 2) : genreStr; 
     genre.setText(genreStr); 

     // release year 
     year.setText(String.valueOf(m.getYear()));*/ 

     return convertView; 
    } 

Movie.java

public class Movie { 
    private String name, thumbnailUrl; 
    //private int year; 
    private String average_ratings,area,cuisine,address; 
// private ArrayList<String> genre; 

    public Movie() { 
    } 

    public Movie(String name, String thumbnailUrl, String average_ratings,String area,String cuisine,String address 
      ) { 
     this.name = name; 
     this.thumbnailUrl = thumbnailUrl; 
     //this.year = year; 
     this.average_ratings = average_ratings; 
     this.area=area; 
     this.cuisine=cuisine; 
this.address=address; 
     //this.genre = genre; 
    } 

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 

    public String getThumbnailUrl() { 
     return thumbnailUrl; 
    } 

    public void setThumbnailUrl(String thumbnailUrl) { 
     this.thumbnailUrl = thumbnailUrl; 
    } 

    /*public int getYear() { 
     return year; 
    }*/ 

    /*public void setYear(int year) { 
     this.year = year; 
    }*/ 

    public String getAverage_ratings() { 
     return average_ratings; 
    } 

    public void setAverage_ratings(String average_ratings) { 
     this.average_ratings = average_ratings; 
    } 
    public String getAddress() { 
     return address; 
    } 

    public void setAddress(String address) { 
     this.address = address; 
    } 

    public String getCuisine() { 
     return cuisine; 
    } 

    public void setCuisine(String cuisine) { 
     this.cuisine = cuisine; 
    } 
    /*public ArrayList<String> getGenre() { 
     return genre; 
    } 

    public void setGenre(ArrayList<String> genre) { 
     this.genre = genre; 
    } 
*/ 
} 

Answer 1

創建地址模型類：

Address.java：

class Address { 

    private String area; 
    private String fullAddress; 

    public void set(String are){this.area = area;} 
    public void set(String are){this.fullAddress= fullAddress;} 

    public String getArea(){return area;} 
    public String getFullAddress(){return fullAddress;} 

} 

你應該在電影模式類地址setter和getter方法。 只解析主json的地址json對象，就像明智的你必須從主json Object解析其他對象。

JSON解析：

    // Parsing json 
        for (int i = 0; i < response.length(); i++) { 
         try { 

          JSONObject obj = response.getJSONObject(i); 
          Movie movie = new Movie(); 
          //movie.setTitle(obj.getString("title")); 
          movie.setName(obj.getString("name")); 
          //movie.setThumbnailUrl(obj.getString("image")); 
          movie.setThumbnailUrl(obj.getString("image_url")); 
          movie.setAverage_ratings(obj.getString("average_ratings")); 
          movie.setCuisine(obj.getString("cuisine")); 
          //movie.setYear(obj.getInt("releaseYear")); 
          if(obj.has("address")){ 
           JSONObject addressJsonObj = obj.getJSONObject("address"); 
           Address address = new Address(); 
           address.setArea(addressJsonObj.getString("area")); 
           address.setFullAddress(addressJsonObj.getString("full_address")); 
           movie.setAddress(address); 
          } 

          // adding movie to movies array 
          movieList.add(movie); 

         } catch (JSONException e) { 
          e.printStackTrace(); 
         } 

        } 

Answer 2

OBJ創建後：

JSONObject adressObject = obj.getJSONObject("adress"); 
String area = adressObject.get("area").toString();