Как реализовать listview с фрагментом, пользовательским адаптером, вкладками и просмотрщиком в Android

Я пытаюсь реализовать действие с просмотрщиком и двумя вкладками, чтобы разрешить жесты пролистывания между разделами, каждый из которых содержит список с пользовательским адаптером, который загружает данные из асинхронной задачи. Я хотел бы показать счетчик загрузки при загрузке данных.

Если мы используем обычный список с простым адаптером, он работает. Проблема возникает, когда мы вводим собственный адаптер для списков. Eclipse возвращает следующую ошибку:

НЕИСПРАВНОЕ ИСКЛЮЧЕНИЕ: основное java.lang.NullPointerException в библиотеках.BoostAdapter.getCount(BoostAdapter.java:58) в android.widget.ListView.setAdapter(ListView.java:466) в kasuga.gamble.roma.LikeAttendList$AppSectionsPagerAdapter$LikeFragmentList. onActivityCreated(LikeAttendList.java:237) в android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:891) в android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1080) в android.support .v4.app.BackStackRecord.run(BackStackRecord.java:622) [...]

Любые советы будут приветствоваться! Спасибо.

• Активность (для простоты рассмотрим только один ListFragment)

    public class LikeAttendList extends FragmentActivity implements ActionBar.TabListener 
    {
     AppSectionsPagerAdapter mAppSectionsPagerAdapter;
     //ListView Adapter
     static BoostAdapter adapterLike;
     static BoostAdapter adapterAttend;
     ViewPager mViewPager;
  
     public void onCreate(Bundle savedInstanceState) 
     {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.attendlike);
  
      //Retrieve intent extras: event Id
      Intent i2 = getIntent(); 
  
      uid = i2.getExtras().getString("eventid");
  
      //Adapter creation
      Log.e("LikeAttend Report", "Entering LikeAttendList, eventID: " + uid);
      // Create the adapter that will return a fragment for each of the two sections
      // of the app.
      mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());
  
      // Set up the action bar.
      final ActionBar actionBar = getActionBar();
  
      // Specify that the Home/Up button should not be enabled, since there is no hierarchical
      // parent.
      actionBar.setHomeButtonEnabled(false);
  
      // Specify that we will be displaying tabs in the action bar.
      actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
  
      // Set up the ViewPager, attaching the adapter and setting up a listener for when the
      // user swipes between sections.
      mViewPager = (ViewPager) findViewById(R.id.pager);
      mViewPager.setAdapter(mAppSectionsPagerAdapter);
      mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() 
      {
          @Override
          public void onPageSelected(int position) 
          {
              // When swiping between different app sections, select the corresponding tab.
              // We can also use ActionBar.Tab#select() to do this if we have a reference to     the
              // Tab.
              actionBar.setSelectedNavigationItem(position);
          }
      });
  
      // For each of the sections in the app, add a tab to the action bar.
      for (int i = 0; i < mAppSectionsPagerAdapter.getCount(); i++) 
      {
          // Create a tab with text corresponding to the page title defined by the adapter.
          // Also specify this Activity object, which implements the TabListener interface, as the
          // listener for when this tab is selected.
          actionBar.addTab(
                  actionBar.newTab()
                          .setText(mAppSectionsPagerAdapter.getPageTitle(i))
                          .setTabListener(this));
      }
    }
  
    /**
     * A FragmentPagerAdapter that returns a fragment corresponding to one of the primary
     * sections of the app.
     */
    public static class AppSectionsPagerAdapter extends FragmentPagerAdapter 
    {
  
      public AppSectionsPagerAdapter(FragmentManager fm) 
      {
          super(fm);
      }
  
      @Override
      public Fragment getItem(int i) 
      {
          switch (i) 
          {
          case 0:
                  // The first section of the app shows all likes.
                  return new LikeFragmentList();
  
                 //The second should show all user who will attend the event
          default:
              // The other sections of the app are dummy placeholders.
              Fragment fragment = new DummySectionFragment();
              Bundle args = new Bundle();
              args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, i + 1);
              fragment.setArguments(args);
              return fragment;
          }
      }
      public static class LikeFragmentList extends ListFragment 
      {
          private ListView listv;
          private BoostAdapter adapter;
  
          @Override
          public void onCreate(Bundle savedInstanceState) 
          {
              super.onCreate(savedInstanceState);
  
                  //retrieves data from asyncTask
              LikeAttendList mc = new LikeAttendList();
              mc. new EventDataTask().execute(uid);
                  //Sets up the adapter 
              Activity ctx = this.getActivity();
              adapterLike = new BoostAdapter(ctx, userList);
  
          }
  
          @Override
          public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) 
          {
  
              View v1 = inflater.inflate(R.layout.likelist, container, false);
  
              listv = (ListView) v1.findViewById(android.R.id.list);
              return v1;
  
          }
  
          @Override
          public void onActivityCreated(Bundle savedInstanceState) 
          {
              super.onActivityCreated(savedInstanceState);
              //ArrayAdapter<String> adapter = new ArrayAdapter<String>(inflater.getContext(), android.R.layout.simple_list_item_1,countries);
  
              listv.setAdapter(adapterLike);
  
              /* Trying to implement a cross fade transition, we should use an xml with the listview and the loading spinner, all advices
              //Cross Fade transition views
              // save the content
              mContentView = getView().findViewById(R.id.likelist);
  
              // save the loading spinner
              mLoadingView = getView().findViewById(R.id.loading_spinner);
  
              // remove content
              mContentView.setVisibility(View.GONE);
  
              // save the animation duration
              mAnimationDuration = getResources().getInteger(android.R.integer.config_longAnimTime);
              */
          }
      }
  
      public String[] titles=
      {
         "Likes",
         "Attends"
      };
  
      @Override
      public int getCount() 
      {
          return titles.length;
      }
  
      @Override
      public CharSequence getPageTitle(int position) 
      {
          return titles[position];
      }
    }
  
    public static class DummySectionFragment extends Fragment 
    {
      public static final String ARG_SECTION_NUMBER = "section_number";
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) 
      {
          View rootView = inflater.inflate(R.layout.fragment_section_dummy, container, false);
          Bundle args = getArguments();
          ((TextView) rootView.findViewById(android.R.id.text1)).setText(
                  getString(R.string.dummy_section_text, args.getInt(ARG_SECTION_NUMBER)));
          return rootView;
      }
    }
  
    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) 
    {
      // TODO Auto-generated method stub
    }
  
    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) 
    {
        // When the given tab is selected, switch to the corresponding page in the ViewPager.
        mViewPager.setCurrentItem(tab.getPosition());
    }
  
    @Override
     public void onTabUnselected(Tab tab, FragmentTransaction ft) 
    {
  
    }
  
    private class EventDataTask extends AsyncTask<String, Void, JSONObject> 
    {
      //Returns a ArrayList<HashMap<String, String>> with datas called userlist used to populate listview. cf: onCreate in LikeFragmentList()
       private View mContent;
   private View mSpinner;
   private int mDuration;
  
   public EventDataTask() 
   {
  
       eventsFunctions = new EventsFunctions();
   }
  
       protected JSONObject doInBackground(String... uid) 
       {
  Log.e("Social","List Requested: num item: " + max_item +" page number: " + current_page );
  // getting JSON string from URL
      current_page=1;
      String eventId=uid[0];
      return eventsFunctions.eventList(Integer.toString(current_page),Integer.toString(max_item),TAG_ACTIVITY, eventId );
       }
  
       @Override
       protected void onPostExecute(JSONObject json) 
   {
      // Check your log cat for JSON reponse
      //Log.e("All Socials list data Once: ", json.toString());
  
      userList = new ArrayList<HashMap<String, String>>();
  
  try 
      {
           // Checking for SUCCESS TAG
           String success = json.getString(TAG_SUCCESS);
           if (success != null) 
           {
               if (Integer.parseInt(json.getString(TAG_SUCCESS)) != 0)
               {
                   JSONArray like = json.getJSONArray("likes");
                  for (int i = 0; i < like.length(); i++) 
                  {
                          JSONObject c = like.getJSONObject(i);
  
                          String name     = c.getString(TAG_NAME);
                          String score    = c.getString(TAG_SCORE);
                          String photo    = c.getString(TAG_PHOTO);
  
                          // creating new HashMap
                          HashMap<String, String> firstItemMap = new HashMap<String, String>();
  
                          // adding each child node to HashMap key => value
                          firstItemMap.put(TAG_SCORE, score);
                          firstItemMap.put(TAG_NAME, name);
                          firstItemMap.put(TAG_PHOTO, photo);
  
                          // adding HashList to ArrayList 
                          userList.add(firstItemMap);
  
                   }
  
                           for (int j=0; j< userList.size(); j++ )
                      {
                          //Log.e("AllEvents Reporter", "Torneo numero: "+ j + " Nome: " + tornei.get(j).getName());
                          Log.e("Social Reporter", "utente numero: "+ j + " Nome: " + userList.get(j).get(TAG_NAME));
                      }
               }  
             }
      }
      catch (JSONException e) 
      {
          e.printStackTrace();
      }
  super.onPostExecute(json);
     }
    }
  }
  

-Custom BoostAdapter создан:

    public class BoostAdapter extends BaseAdapter 
{
        private static String logo_path = "http://userk.servehttp.com/Gamble/Immagini/Pokeroom/All/";

    // JSON Node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_PEOPLE = "people";
    private static final String TAG_UID = "uid";
    private static final String TAG_NAME = "name";
    private static final String TAG_RANKING = "ranking";
    private static final String TAG_PROFILEPICTURE = "photo";
    private static final String TAG_EVENTUID = "eventuid";

    EventsFunctions eventsFunctions;
    Bitmap bitmapLogo;
    Bitmap bit;
    private static LayoutInflater inflater=null;

    public ImageLoader imageLoader; 
    private ArrayList<HashMap<String, String>> people;
    private Activity context;

    public BoostAdapter() 
    {
        super();
    }

    public BoostAdapter(Activity ctx, ArrayList<HashMap<String, String>> persons) 
    {
        super();
        context = ctx;
        people = persons;
        inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader=new ImageLoader(context.getApplicationContext());
    }

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

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

    public long getItemId(int position) 
    {
        return position;
    }
    static class ViewHolder 
    {
        public TextView row_name;
        public TextView rankinglist;
        public ImageView image;
    }



    public View getView(int position, View convertView, ViewGroup parent) 
    {
        View vi=convertView;
        if(convertView==null)   
        {
            LayoutInflater inflater = ((Activity) context).getLayoutInflater();
            vi = inflater.inflate(R.layout.list_item, null);
            ViewHolder viewholder = new ViewHolder();
            viewholder.row_name= (TextView) vi.findViewById(R.id.row_name);
            viewholder.rankinglist= (TextView) vi.findViewById(R.id.rankinglist);
            viewholder.image = (ImageView) vi.findViewById(R.id.row_icon);
            vi.setTag(viewholder);
        }

        //Log.e("BassAdapter Reporter","Checking infos retrivial: Received event: " + Integer.toString(position) + " of " +Integer.toString(tornei.size()) + 
        //      " Infos:\n Name: "+ tornei.get(position).get(TAG_NAME) + " logo: " +  tornei.get(position).get(TAG_LOGO) +" Gtd: " + tornei.get(position).get(TAG_GTD).length() +"Buyin: "+ tornei.get(position).get(TAG_BUYIN) + "  partecipanti " + tornei.get(position).get(TAG_PARTECIPANTI));  

        ViewHolder holder = (ViewHolder) vi.getTag();
        holder.row_name.setText(people.get(position).get(TAG_NAME));
        holder.row_name.setMaxLines(1);
        holder.rankinglist.setText(people.get(position).get(TAG_RANKING));
        if (people.get(position).get(TAG_PROFILEPICTURE)!="")
        {
            String url2 = logo_path + people.get(position).get(TAG_PROFILEPICTURE);
            //Log.e(" Adapter report:", tornei.get(position).getName() + " and its image path is " + url2);
            Log.e("Adapter report:", "Item " + Integer.toString(position) + " of " +Integer.toString(people.size()));
            imageLoader.DisplayImage(url2, holder.image);
        }
        return vi;
    }
          }

Это требуемый xml:

• список избранных

<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:listSelector="@drawable/list_selector"/>

    <ProgressBar android:id="@+id/loading_spinner_like"
        style="?android:progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center" />

</LinearLayout>

• attllike.xml

  <android.support.v4.view.ViewPager
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />
  

• присутствовать

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:orientation="horizontal" 
    android:cacheColorHint="#00000000" >

  <ImageView
        android:id="@+id/row_icon"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:padding="5dp"
        android:src="@drawable/ic_launcher" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:baselineAligned="false"
        android:paddingLeft="7dp"
        android:paddingTop="5dp">

        <TextView
            android:id="@+id/row_name"
            android:layout_width="wrap_content"
            android:layout_height="fill_parent"
            android:text="@string/namelist"
            android:textColor="#000000"
            android:textSize="15sp"
            android:ellipsize="marquee"
          android:scrollHorizontally="true"
            android:textStyle="bold"/> 

        <LinearLayout 
            android:layout_width="wrap_content"
            android:layout_height="fill_parent">

            <TextView
                android:id="@+id/ramkingList"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:text="@string/rankinglist"
                android:textColor="#000000"
                android:textSize="14sp" />

            <TextView
                android:id="@+id/rankinglist"
                android:layout_width="wrap_content"
                android:layout_height="fill_parent"
                android:text="@string/rankingexample"
                android:textColor="#000000"
                android:textSize="14sp" />


        </LinearLayout>
    </LinearLayout>
</LinearLayout>