java - Android - 将 JSON 加载到 ListView

Question

我对 Android 开发还是很陌生，正在做一个应用程序/项目，其中涉及将这个 JSON（下面列出）加载到一个ListView带有名称、描述和图像的文件中，但它在模拟器上一直是空白的。请告诉我我做错了什么 - 任何帮助将不胜感激！（越具体越好，因为我是新手..）

JSON：

 {
   "success":true,
   "games":[
      {
         "id":"1",
         "name":"Name of the Game",
         "description":"This is what it is about",
         "image":"IMAGE URL"
      }
   ]
}

AndroidJSONParsingActivity：

// URL to make request
    private static final String url = "URL of API";

    // JSON Node names
    private static final String TAG_GAMES = "games";
    private static final String TAG_ID = "id";
    private static final String TAG_NAME = "name";
    private static final String TAG_DESCRIPTION = "description";
    private static final String TAG_IMAGE = "image";

    // games JSONArray
    JSONArray games = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

    // Hash map for ListView
                ArrayList<HashMap<String, String>> gameList = new ArrayList<HashMap<String, String>>();

            // Creating JSON Parser instance
            JSONParser jParser = new JSONParser();

            // getting JSON string from URL
            JSONObject json = jParser.getJSONFromUrl(url);

            try {
                // Getting Array of Games
                games = json.getJSONArray(TAG_GAMES);

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

                    // Storing each JSON item in variable
                    String id = c.getString(TAG_ID);
                    String image = c.getString(TAG_IMAGE);

                    // is again JSON Object
                    JSONObject author = c.getJSONObject(TAG_DESCRIPTION);
                    String name = author.getString(TAG_NAME);

                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_ID, id);
                    map.put(TAG_NAME, name);
                    map.put( TAG_IMAGE, image);
                    // adding HashList to ArrayList
                    gameList.add(map);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }


            /**
             * Updating parsed JSON data into ListView
             * */
            ListAdapter adapter = new SimpleAdapter(this, gameList,
                    R.layout.list_item,
                    new String[] { TAG_NAME, TAG_DESCRIPTION }, new int[] {
                            R.id.name, R.id.description });

            setListAdapter(adapter);

            // selecting single ListView item
            ListView lv = getListView();

            // Launching new screen on Selecting Single ListItem
            lv.setOnItemClickListener(new OnItemClickListener() {

                public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {
                    // getting values from selected ListItem
                    String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
                    String description = ((TextView) view.findViewById(R.id.description)).getText().toString();

                    // Starting new intent
                    Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
                    in.putExtra(TAG_NAME, name);
                    in.putExtra(TAG_DESCRIPTION, description);
                    startActivity(in);

                }
            });



        }

JSON解析器：

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

主.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
    <!-- Main ListView 
         Always give id value as list(@android:id/list)
    -->
    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

list_item.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <!-- Name Label -->
    <TextView
        android:id="@+id/name"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:textColor="#43bd00"
        android:textSize="16sp"
        android:textStyle="bold"
        android:paddingTop="6dip"
        android:paddingBottom="2dip" />
        <TextView
            android:id="@+id/description"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:textColor="#acacac"
            android:paddingBottom="2dip" />
        </LinearLayout>

添加 LogCat 信息：

01-03 06:16:15.254: E/ActivityThread(616): Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d47b40 that was originally bound here
01-03 06:16:15.254: E/ActivityThread(616): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d47b40 that was originally bound here
01-03 06:16:15.254: E/ActivityThread(616):  at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
01-03 06:16:15.254: E/ActivityThread(616):  at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
01-03 06:16:15.254: E/ActivityThread(616):  at android.app.ContextImpl.bindService(ContextImpl.java:1418)
01-03 06:16:15.254: E/ActivityThread(616):  at android.app.ContextImpl.bindService(ContextImpl.java:1407)
01-03 06:16:15.254: E/ActivityThread(616):  at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
01-03 06:16:15.254: E/ActivityThread(616):  at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
01-03 06:16:15.254: E/ActivityThread(616):  at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
01-03 06:16:15.254: E/ActivityThread(616):  at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
01-03 06:16:15.254: E/ActivityThread(616):  at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
01-03 06:16:15.254: E/ActivityThread(616):  at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
01-03 06:16:15.254: E/ActivityThread(616):  at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
01-03 06:16:15.254: E/ActivityThread(616):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
01-03 06:16:15.254: E/ActivityThread(616):  at java.util.concurrent.FutureTask.run(FutureTask.java:234)
01-03 06:16:15.254: E/ActivityThread(616):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
01-03 06:16:15.254: E/ActivityThread(616):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
01-03 06:16:15.254: E/ActivityThread(616):  at java.lang.Thread.run(Thread.java:856)
01-03 06:16:15.365: E/StrictMode(616): null
01-03 06:16:15.365: E/StrictMode(616): android.app.ServiceConnectionLeaked: Service com.android.exchange.ExchangeService has leaked ServiceConnection com.android.emailcommon.service.ServiceProxy$ProxyConnection@40d47b40 that was originally bound here
01-03 06:16:15.365: E/StrictMode(616):  at android.app.LoadedApk$ServiceDispatcher.<init>(LoadedApk.java:969)
01-03 06:16:15.365: E/StrictMode(616):  at android.app.LoadedApk.getServiceDispatcher(LoadedApk.java:863)
01-03 06:16:15.365: E/StrictMode(616):  at android.app.ContextImpl.bindService(ContextImpl.java:1418)
01-03 06:16:15.365: E/StrictMode(616):  at android.app.ContextImpl.bindService(ContextImpl.java:1407)
01-03 06:16:15.365: E/StrictMode(616):  at android.content.ContextWrapper.bindService(ContextWrapper.java:473)
01-03 06:16:15.365: E/StrictMode(616):  at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:157)
01-03 06:16:15.365: E/StrictMode(616):  at com.android.emailcommon.service.ServiceProxy.setTask(ServiceProxy.java:145)
01-03 06:16:15.365: E/StrictMode(616):  at com.android.emailcommon.service.ServiceProxy.test(ServiceProxy.java:191)
01-03 06:16:15.365: E/StrictMode(616):  at com.android.exchange.ExchangeService$7.run(ExchangeService.java:1850)
01-03 06:16:15.365: E/StrictMode(616):  at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:551)
01-03 06:16:15.365: E/StrictMode(616):  at com.android.emailcommon.utility.Utility$2.doInBackground(Utility.java:549)
01-03 06:16:15.365: E/StrictMode(616):  at android.os.AsyncTask$2.call(AsyncTask.java:287)

Answer 1

这是我的代码

public class as extends AsyncTask   {

            public as(int aa)       {
                        }

            @Override       protected Object doInBackground(Object... params)       {           //int price1,sp1,save1;             try             {           JSONObject json = JSONfunctions.getJSONfromURL("http://192.168.1.97/inventory/Client.php?action=productlist&page_no="+aa+"&user_id="+userid+"");            Log.e("url", String.valueOf("http://192.168.1.97/inventory/Client.php?action=productlist&page_no="+aa+"&user_id="+userid+""));          mylist = new ArrayList<HashMap<String, String>>();
                try{
                    JSONArray  products = json.getJSONArray("product");
                    Log.v("inside", "inside");

                    Log.e("pages",String.valueOf( json.get("products_count")));
                    pagecount=json.getInt("page_count");

                    //JSONObject e1 = pages.getJSONObject("tot_pages");

                //  Log.e("totpages",e1.getString("tot_pages"));
                //  pagecount=json.getInt("tot_pages");
                    // pcount=json.getInt("p_count");


                    for(int i=0;i<products.length();i++){   
                        String img,img1;
                        HashMap<String, String> map = new HashMap<String, String>();    
                        Log.e("p c",String.valueOf(i));
                        JSONObject e = products.getJSONObject(i);
                        Log.v("name", String.valueOf(e.getString("name")));
                        map.put("name",e.getString("name"));
                        map.put("price",e.getString("price"));
                        map.put("sp",e.getString("special_price"));
                        map.put("image", String.valueOf(e.getString("image")));
                    float price1 = Float.parseFloat(e.getString("price"));
                    float sp1=Float.parseFloat(e.getString("special_price"));
                    float save1=price1-sp1;
                    map.put("save",String.valueOf(save1));


                        mylist.add(map);    

                    }       
                }catch(JSONException e)
                {
                     Log.e("log_tag", "Error parsing data "+e.toString());

                }



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





             }
                            return null;




                        }

            @Override       protected void onPostExecute(Object result)         {           //lv.setAdapter(new ItemListBaseAdapter(AllItems.this, mylist));
                        }




            @Override       protected void onPreExecute()       {           try{            progressDialog = ProgressDialog.show(AllItems.this, "", "Please wait");             }           catch (Exception e) {


                    e.printStackTrace();

                                }           super.onPreExecute();       }

        }       //previous check method


                public class ItemListBaseAdapter extends BaseAdapter {

                    private  ArrayList<HashMap<String, String>> itemDetailsrrayList;         Bitmap bitmap[];           Context context1;           String ab;



                        private LayoutInflater l_Inflater;

            public ItemListBaseAdapter(Context context, ArrayList<HashMap<String, String>> mylist)      {
                            itemDetailsrrayList = mylist;           //l_Inflater = LayoutInflater.from(context);            context1=context;
                }

            public int getCount() {             return itemDetailsrrayList.size();
                        }

            public Object getItem(int position) {           return itemDetailsrrayList.get(position);       }

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



                    public View getView( final int position, View convertView, ViewGroup parent)        {
              int ruban=3;
                        //final ViewHolder holder;

                        if (convertView == null) {
                    l_Inflater = LayoutInflater.from(context1);

                     convertView = l_Inflater.inflate(R.layout.list1, null,true);



                                }

                            TextView txt_itemName = (TextView) convertView.findViewById(R.id.textView1);            TextView txt_itemDescription = (TextView) convertView.findViewById(R.id.mrp1);          TextView txt_itemPrice = (TextView) convertView.findViewById(R.id.ourprice1);           TextView txt_itemSave = (TextView) convertView.findViewById(R.id.save1);            //holder.txt_itemw = (TextView) convertView.findViewById(R.id.textView4);           WebView itemimmm=(WebView)convertView.findViewById(R.id.imageView1);            TextView t1 = (TextView) convertView.findViewById(R.id.t1);             TextView t2 = (TextView) convertView.findViewById(R.id.t2);             TextView t3 = (TextView) convertView.findViewById(R.id.t3);             ImageView addprod=(ImageView)convertView.findViewById(R.id.addprod);            final Button decprod=(Button)convertView.findViewById(R.id.decprod);
                final TextView disprod=(TextView)convertView.findViewById(R.id.disprod);            decprod.setVisibility(View.INVISIBLE);          disprod.setVisibility(View.INVISIBLE);
                            txt_itemDescription.setPaintFlags(txt_itemDescription.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);           itemimmm.getSettings().setLayoutAlgorithm(LayoutAlgorithm.SINGLE_COLUMN);
                            txt_itemName.setTypeface(AllItems.face);            txt_itemDescription.setTypeface(AllItems.face);             txt_itemPrice.setTypeface(AllItems.face);           txt_itemSave.setTypeface(AllItems.face);            //holder.txt_itemw.setTypeface(AllItems.face);          t1.setTypeface(AllItems.rupee);
                t2.setTypeface(AllItems.rupee);
                t3.setTypeface(AllItems.rupee);
                //StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
                //StrictMode.setThreadPolicy(policy);           txt_itemName.setText(itemDetailsrrayList.get(position).get("name"));            txt_itemDescription.setText(itemDetailsrrayList.get(position).get("price"));            txt_itemPrice.setText(itemDetailsrrayList.get(position).get("sp"));
                txt_itemSave.setText(itemDetailsrrayList.get(position).get("save"));            //holder.txt_itemw.setText(itemDetailsrrayList.get(position).get("type"));
                itemimmm.loadUrl(itemDetailsrrayList.get(position).get("image"));           if(itemDetailsrrayList.get(position).get("name").equals("Daughter")||itemDetailsrrayList.get(position).get("name").equals("Ethnic"))            {
                Log.e("name", String.valueOf(itemDetailsrrayList.get(position).get("name")));           //decprod.setVisibility(View.VISIBLE);          //disprod.setVisibility(View.VISIBLE);          }

                  // Log.e("before", "try");

                        /*  try{

                        Log.e("try", String.valueOf(itemDetailsrrayList.get(position).get("image")));
                     Bitmap bitmap1 = BitmapFactory.decodeStream((InputStream) new URL(itemDetailsrrayList.get(position).get("image")).getContent());
                     itemimmm.setImageBitmap(bitmap1);
                    }catch(Exception ex){

                         ex.printStackTrace();
                         Log.e("error",String.valueOf(ex));
                     itemimmm.setImageResource(getResources().getIdentifier("ic_launcher", "drawable", getPackageName())); 

                        Log.e("catch", "catch");*/

                //prodImage.setImageResource(getResources().getIdentifier("sample", "drawable", getPackageName()));


                //itemimmm.setImageResource(getResources().getIdentifier("ic_launcher", "drawable", getPackageName())); 



                    //holder.itemImage.setImageBitmap(bitmap[position]);

                              addprod.setOnClickListener(new OnClickListener() {
                                @Override
                    public void onClick(View arg0)          {


                       //decprod.setVisibility(View.VISIBLE);
                        //disprod.setVisibility(View.VISIBLE);



                                       /*   int k = 0;
                                        if(disprod.getText()!="" || disprod.getText()!=null){
                                            k = Integer.parseInt(String.valueOf(disprod.getText()));
                                        }
                                        disprod.setText(String.valueOf(++k));
                                        disprod.setTag(k);*/
                                       Log.v("position", String.valueOf(position));


                                new AddCart(decprod,disprod).execute();




                    }           });   




                decprod.setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View arg0)
                    {
                        //Log.v("item name", String.valueOf(itemDetailsrrayList.get(position).get("price")));

                    }           });




               /* textView.setText(getelement()[position]);

                 ImageView imageView = (ImageView) convertView
                .findViewById(R.id.icon);
                 imageView.setImageBitmap(bitmap);*/




                    return convertView;




                   }

Answer 2

AsyncTask.class

class LoadMovies extends AsyncTask<Void, Void, List<Category>>{

private YourActivity activity;

public LoadMovies(YourActivity activty){
    activity = activty;
}

        private final static String TAG = "Log";


        @Override
        protected List<Category> doInBackground(Void... params) {
            InputStream ips = null;
            JSONObject json = null;

            try{
                DefaultHttpClient client = new DefaultHttpClient();
                HttpResponse response = client.execute(new HttpGet("http://youtsite"));

                ips = response.getEntity().getContent();
                BufferedReader buffer = new BufferedReader(new InputStreamReader(ips));
                StringBuilder builder = new StringBuilder();
                String line;

                while((line = buffer.readLine()) != null){
                    builder.append(line+"\n");
                }
                json = new JSONObject(builder.toString());

            }
            catch(Exception e){
                Log.i(TAG, e.toString());
            }

                List<Category> list = new ArrayList<Category>();
                JSONArray array = json.optJSONObject("data").optJSONArray("reviews");
                for (int i = 0; i < array.length(); i++){
                    JSONObject rss = array.optJSONObject(i); 
                                    Category cat = new Category();
                                    cat.addName(rss.optString("name"));  
                                    cat.addCode(rss.optString("code"));                     
                    list.add(cat);
                }

            return list;
        }

        protected void onPostExecute(List<Category> result){
            super.onPostExecute(result);
                    Youractivity.mMoviesAdapter.addCategory(result);
        }

    }

类别.class

public class Category {
    private String name;
    private String code;

    void addName(String name){
        this.name = name;
    }

    void addCode(String code){
        this.code = code;
    }

    public String getName(){
     return this.name;
    }

    String getCode(){
        return this.code;
    }
}

适配器类

class MoviesAdapter extends ArrayAdapter<Category> {

    Context c;      
    List<Category> mListCategory; 

    public MoviesAdapter(Context context, int resource, int textViewResource, List<Categoryy> list) {
        super(context, resource, textViewResource, list);
        c = context;

        mListCategory= list;
    }

    public void addCategory(List<MoviesCategory> list){
        mListCategory.addAll(list);
        notifyDataSetChanged();
    }

    @Override
     public View getView(int position, View convertView, ViewGroup parent){
        View v = convertView;
        if(v == null){
            LayoutInflater inflater = LayoutInflater.from(c);
            v = inflater.inflate(R.layout.yourview, null);
        }

        TextView title =  (TextView) v.findViewById(R.id.title);
        TextView code=  (TextView) v.findViewById(R.id.code);

        Category cat = getItem(position);
        if(mov != null){
            title.setText(cat.getName());
            code.setText(cat.getCode());

        }

        return v;
    }   

}

并在 MainActivity 调用所有

    public class YourActivity extends MainActivity{
    private ListView mCategory;
    private List<Category> mCategoryArray = new ArrayList<Category>();
    private LoadMovies mLoadMovies;
    public mMoviesAdapter adapter;

   @Override
   protected void onCreate(Bundle bundle){
   super.onCreate(bundle);

    //MoviesList        
        mMoviesAdapter = new MoviesAdapter(this, R.layout.main_movies_adapter, R.id.youradapterlayout, mCategoryArray );
        mCategoryList = (ListView) findViewById(R.id.movies_adapter_list);
        mMoviesList.setAdapter(mMoviesAdapter);

        mLoadMovies = new LoadMovies(this);
        mLoadMovies.execute();
}
    }