陣列適配器返回null

我有兩個適配器和一個片段，並且我想在兩個視圖，一個底部和一個回收器視圖上顯示源。雖然Json正在使用列表適配器。它沒有與回收者的觀點一起工作。陣列適配器返回null

這裏是主要片段

import it.gmariotti.cardslib.library.internal.Card; 
import it.gmariotti.cardslib.library.internal.CardExpand; 
import it.gmariotti.cardslib.library.internal.CardHeader; 
import it.gmariotti.cardslib.library.view.CardViewNative; 
import jp.co.recruit_lifestyle.android.widget.WaveSwipeRefreshLayout; 


public class FeedFragmentAlternative extends Fragment{ 
private static final String TAG = FeedFragmentAlternative.class.getSimpleName(); 

private String URL_FEED = "http://api.androidhive.info/feed/feed.json"; 

private WaveSwipeRefreshLayout mWaveSwipeRefresh; 
int duration = 200; 

private List<FeedItem> FeedItems; 

public static FeedFragmentAlternative newInstance(){ 
    FeedFragmentAlternative feedFragmentAlternative = new FeedFragmentAlternative(); 
    return feedFragmentAlternative; 
} 

private void refresh(){ 
    new Handler().postDelayed(new Runnable() { 
     @Override 
     public void run() { 
      mWaveSwipeRefresh.setRefreshing(false); 
     } 
    },3000); 
} 

private ExpandablePager pager; 

@Nullable 
@Override 
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
    View view = inflater.inflate(R.layout.feed_activity_alternate, container, false); 
    final List<FeedItem> myFeedList = new ArrayList<>(); 
    final FeedExpandableAdapter adapter = new FeedExpandableAdapter(myFeedList); 
    pager = (ExpandablePager) getActivity().findViewById(R.id.bottom_feed_container); 
    pager.setAdapter(adapter); 
    pager.setOnSliderStateChangeListener(new OnSliderStateChangeListener() { 
     @Override 
     public void onStateChanged(View page, int index, int state) { 
      toggleContent(page, state, duration); 
     } 

     @Override 
     public void onPageChanged(View page, int index, int state) { 
      toggleContent(page, state, 0); 
     } 
    }); 

    final RecyclerView mRecyclerView = (RecyclerView) getActivity().findViewById(R.id.feeds_list_recycler_view); 
    mRecyclerView.setHasFixedSize(true); 

    final FeedGridAdapter a = new FeedGridAdapter(myFeedList); 
    a.setListener(new OnItemClickedListener() { 
     @Override 
     public void onItemClicked(int index) { 
      pager.setCurrentItem(index, false); 
      pager.animateToState(ExpandablePager.STATE_EXPANDED); 
     } 
    }); 

    mWaveSwipeRefresh = (WaveSwipeRefreshLayout)view.findViewById(R.id.feed_wave_swipe_layout_refresh_alternate); 
    mWaveSwipeRefresh.setColorSchemeColors(Color.WHITE, Color.GREEN); 
    mWaveSwipeRefresh.setOnRefreshListener(new WaveSwipeRefreshLayout.OnRefreshListener() { 
     @Override 
     public void onRefresh() { 
      pager.setAdapter(adapter); 
      mRecyclerView.setAdapter(a); 
      FeedFragmentAlternative.newInstance(); 
      refresh(); 
     } 
    }); 

    mWaveSwipeRefresh.setWaveColor(Color.parseColor("#80C5EFF7")); 
    mWaveSwipeRefresh.setMaxDropHeight((int)(mWaveSwipeRefresh.getHeight() * 0.9)); 
    mRecyclerView.setAdapter(a); 

    Cache cache = AppController.getInstance().getRequestQueue().getCache(); 
    Cache.Entry entry = cache.get(URL_FEED); 
    if (entry != null){ 
     try { 
      String data = new String (entry.data, "UTF-8"); 
      try { 
       parseJsonFeed(new JSONObject(data)); 
      } catch (JSONException e){ 
       e.printStackTrace(); 
      } 
     }catch (UnsupportedEncodingException e){ 
      e.printStackTrace(); 
     } 
    } else { 
     JsonObjectRequest jsonReq = new JsonObjectRequest(Request.Method.GET, 
       URL_FEED, null, new Response.Listener<JSONObject>() { 
      @Override 
      public void onResponse(JSONObject response) { 
       VolleyLog.d(TAG, "Response:" + response.toString()); 
       if (response != null){ 
        parseJsonFeed(response); 
       } 
      } 
     },new Response.ErrorListener(){ 
      @Override 
      public void onErrorResponse(VolleyError error) { 
       VolleyLog.d(TAG, "ERROR:" + error.getMessage()); 
      } 
     }); 

     AppController.getInstance().addToRequestQueue(jsonReq); 
    } 
    return view; 
} 

private void toggleContent(final View page, final int state, int duration){ 
    final int headerHeight = (int) getResources().getDimension(R.dimen.header_height); 
    if (page != null){ 
     ValueAnimator animator = state == ExpandablePager.STATE_EXPANDED ? ValueAnimator.ofFloat(1,0): ValueAnimator.ofFloat(0,1); 
     animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { 
      @Override 
      public void onAnimationUpdate(ValueAnimator animation) { 
       page.findViewById(R.id.profile_name_header).setTranslationY(25 * (1 - ((Float) animation.getAnimatedValue()))); 
       page.findViewById(R.id.profile_name_header).setTranslationX(-headerHeight * (1 - ((Float)animation.getAnimatedValue()))); 
       page.findViewById(R.id.feed_time_stamp_header).setAlpha(((Float)animation.getAnimatedValue())); 
       page.findViewById(R.id.profile_pic_header_image).setAlpha(((Float)animation.getAnimatedValue())); 
       page.findViewById(R.id.feed_like_bottom_sheet).setAlpha(((Float) animation.getAnimatedValue())); 
      } 
     }); 
     animator.setDuration((long)(duration * 5)); 
     animator.setInterpolator(new FastOutSlowInInterpolator()); 
     animator.start(); 
    } 
} 

private void parseJsonFeed(JSONObject response){ 
    try { 
     JSONArray feedArray = response.getJSONArray("feed"); 
     for (int i = 0;i < feedArray.length(); i++){ 
      JSONObject feedObj = (JSONObject) feedArray.get(i); 

      FeedItem item = new FeedItem(); 
      item.setId(feedObj.getInt("id")); 
      item.setName(feedObj.getString("name")); 

      String image = feedObj.isNull("image")? null : feedObj 
        .getString("image"); 
      item.setImge(image); 
      item.setStatus(feedObj.getString("status")); 
      item.setProfilePic(feedObj.getString("profilePic")); 
      item.setTimeStamp(feedObj.getString("timeStamp")); 

      String feedUrl = feedObj.isNull("url")? null : feedObj 
        .getString("url"); 
      item.setUrl(feedUrl); 

      FeedItems.add(item); 
     } 

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

@Override 
public void onActivityCreated(@Nullable Bundle savedInstanceState) { 
    super.onActivityCreated(savedInstanceState); 

    initCards(); 
} 

private void initCards(){ 
    init_standard_header_with_expandcollapse_button(); 
} 
private void init_standard_header_with_expandcollapse_button(){ 
    Card card = new Card(getActivity()); 
    CardHeader header = new CardHeader(getActivity()); 
    header.setButtonExpandVisible(true); 
    card.addCardHeader(header); 
    CardExpand expand = new CardExpand(getActivity()); 
    expand.setTitle("expanded"); 
    CardViewNative cardViewNative = (CardViewNative) getActivity().findViewById(R.id.feed_card_style); 
    cardViewNative.setCard(card); 
} 
    }

網格適配器是如下

public class FeedGridAdapter extends RecyclerView.Adapter<FeedGridAdapter.ViewHolder> { 
private OnItemClickedListener listener; 
private List<FeedItem> mFeedItems; 
ImageLoader imageLoader = AppController.getInstance().getImageLoader(); 

public static class ViewHolder extends RecyclerView.ViewHolder{ 
    public LoginTextView ProfileNameCell; 
    public LoginTextView FeedTimesStampCell; 
    public NetworkImageView ProfilepicCell; 
    public LoginTextView FeedStatusMgsCell; 
    public FeedImageView FeedImageViewCell; 
    public ViewGroup container; 

    public ViewHolder(RelativeLayout v){ 
     super(v); 
     container = v; 
     ProfileNameCell = (LoginTextView) v.findViewById(R.id.client_name_alternate_cell); 
     FeedTimesStampCell = (LoginTextView) v.findViewById(R.id.time_stamp_alternate_cell); 
     ProfilepicCell = (NetworkImageView) v.findViewById(R.id.profile_pic_alternate_cell); 
     FeedStatusMgsCell = (LoginTextView) v.findViewById(R.id.txtStatusMgs_alternate); 
     FeedImageViewCell = (FeedImageView) v.findViewById(R.id.feedImage1_alternate); 
    } 
} 

public FeedGridAdapter(List<FeedItem> feedItems){mFeedItems = feedItems;} 

@Override 
public FeedGridAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    RelativeLayout v = (RelativeLayout) LayoutInflater.from(parent.getContext()) 
      .inflate(R.layout.feed_card_alternate, parent, false); 
    return new ViewHolder(v); 
} 

@Override 
public void onBindViewHolder(final ViewHolder holder, final int position) { 
    holder.ProfileNameCell.setText(mFeedItems.get(position).getName()); 
    CharSequence timeStampCell = DateUtils.getRelativeTimeSpanString(
      Long.parseLong(mFeedItems.get(position).getTimeStamp()), 
      System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS); 
    holder.FeedTimesStampCell.setText(timeStampCell); 
    if (!TextUtils.isEmpty(mFeedItems.get(position).getStatus())){ 
     holder.FeedStatusMgsCell.setText(mFeedItems.get(position).getStatus()); 
     holder.FeedStatusMgsCell.setVisibility(View.VISIBLE); 
    } else { 
     holder.FeedStatusMgsCell.setVisibility(View.GONE); 
    } 

    holder.ProfilepicCell.setImageUrl(mFeedItems.get(position).getImge(), imageLoader); 

    if (mFeedItems.get(position).getImge() != null){ 
     holder.FeedImageViewCell.setImageUrl(mFeedItems.get(position).getImge(), imageLoader); 
     holder.FeedImageViewCell.setVisibility(View.VISIBLE); 
     holder.FeedImageViewCell 
       .setResponseObserver(new FeedImageView.ResponseObserver() { 
        @Override 
        public void onError() { 

        } 

        @Override 
        public void onSuccess() { 

        } 
       }); 
    } else { 
     holder.FeedImageViewCell.setVisibility(View.GONE); 
    } 
    holder.container.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      if (listener != null) 
       listener.onItemClicked(holder.getAdapterPosition()); 
     } 
    }); 

} 

@Override 
public int getItemCount() { 
    return mFeedItems.size(); 
} 

public void setListener(OnItemClickedListener listener){this.listener = listener;} 

}

和可膨脹片段是

public class FeedExpandableAdapter extends ExpandablePagerAdapter<FeedItem> { 
public FeedExpandableAdapter(List<FeedItem> items){super(items);} 
private LayoutInflater inflater; 
private Activity activity; 
ImageLoader imageLoader = AppController.getInstance().getImageLoader(); 

@Override 
public Object instantiateItem(ViewGroup container, int position) { 
    final ViewGroup rootView = (ViewGroup) LayoutInflater.from(container.getContext()).inflate(R.layout.feed_page_alternative, container, false); 

    if (inflater == null) 
     inflater = (LayoutInflater)activity 
       .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    if (imageLoader == null) 
     imageLoader = AppController.getInstance().getImageLoader(); 

    LoginTextView name = (LoginTextView) rootView.findViewById(R.id.profile_name_header); 
    LoginTextView timestamp = (LoginTextView) rootView.findViewById(R.id.feed_time_stamp_header); 
    NetworkImageView profilepic = (NetworkImageView) rootView.findViewById(R.id.profile_pic_header_image); 

    FeedImageView feedImageView = (FeedImageView) rootView.findViewById(R.id.feed_main_image_bottom_sheet); 

    LoginTextView statusMgs = (LoginTextView) rootView.findViewById(R.id.body_bottom_panel_feed); 

    name.setText(items.get(position).getName()); 

    CharSequence timeofStamp = DateUtils.getRelativeTimeSpanString(
      Long.parseLong(items.get(position).getTimeStamp()), 
      System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS); 
    timestamp.setText(timeofStamp); 

    if (!TextUtils.isEmpty(items.get(position).getStatus())){ 
     statusMgs.setText(items.get(position).getStatus()); 
     statusMgs.setVisibility(View.VISIBLE); 
    } else { 
     statusMgs.setVisibility(View.GONE); 
    } 

    profilepic.setImageUrl(items.get(position).getProfilePic(), imageLoader); 
    if (items.get(position).getImge() != null) { 
     feedImageView.setImageUrl(items.get(position).getImge(), imageLoader); 
     feedImageView.setVisibility(View.VISIBLE); 
     feedImageView 
       .setResponseObserver(new FeedImageView.ResponseObserver() { 
        @Override 
        public void onError() { 
        } 

        @Override 
        public void onSuccess() { 
        } 
       }); 
    } else { 
     feedImageView.setVisibility(View.GONE); 
    } 

    return attach(container, rootView, position); 
} 
}

所示的錯誤是這樣的 -

java.lang.NullPointerException：嘗試在com.evolustudios.askin的空對象引用上調用虛擬方法'void com.telenav.expandablepager.ExpandablePager.setAdapter（android.support.v4.view.PagerAdapter）'。 askin.src.fragments.FeedFragmentAlternative.onCreateView（FeedFragmentAlternative.java:86）

誰能告訴我，爲什麼它返回null？它可能重複，但我想不通爲什麼它返回null

XML - feed_card_alternate

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" android:layout_height="350dp" 
android:paddingTop="10dp" 
android:paddingBottom="10dp"> 
<it.gmariotti.cardslib.library.view.CardViewNative 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:id="@+id/feed_card_style" 
    style="@style/card_external"> 
    <FrameLayout 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:id="@+id/frame_list_card_item_alternate" 
     android:background="@drawable/cardpanel" 
     android:paddingTop="0dp"> 
     <RelativeLayout 
      android:layout_width="match_parent" 
      android:layout_height="wrap_content"> 

      <LinearLayout 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:orientation="horizontal" 
       android:paddingLeft="15dp" 
       android:paddingRight="15dp" 
       android:id="@+id/feed_top_panel_alternate" 
       android:paddingBottom="25dp"> 
       <com.android.volley.toolbox.NetworkImageView 
        android:layout_width="50dp" 
        android:layout_height="50dp" 
        android:id="@+id/profile_pic_alternate_cell" 
        android:scaleType="fitCenter" 
        android:paddingTop="15dp"/> 
       <LinearLayout 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:orientation="vertical" 
        android:paddingLeft="10dp" 
        android:paddingTop="15dp"> 
        <com.evolustudios.askin.askin.src.customfonts.LoginTextView 
         android:layout_width="match_parent" 
         android:layout_height="wrap_content" 
         android:id="@+id/client_name_alternate_cell" 
         android:textSize="15dp" 
         android:textStyle="bold"/> 
        <com.evolustudios.askin.askin.src.customfonts.LoginTextView 
         android:layout_width="match_parent" 
         android:layout_height="wrap_content" 
         android:id="@+id/time_stamp_alternate_cell" 
         android:textColor="@color/timestamp" 
         android:textSize="13dp"/> 
       </LinearLayout> 

      </LinearLayout> 

      <LinearLayout 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:orientation="vertical" 
       android:id="@+id/feed_other_content_alternate" 
       android:layout_below="@+id/feed_top_panel_alternate"> 
       <com.evolustudios.askin.askin.src.customfonts.LoginTextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:id="@+id/txtStatusMgs_alternate" 
        android:paddingBottom="5dp" 
        android:paddingLeft="15dp" 
        android:paddingRight="15dp" 
        android:paddingTop="13dp" /> 
       <com.evolustudios.askin.askin.src.customfonts.LoginTextView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:id="@+id/txtUrl_alternate" 
        android:linksClickable="true" 
        android:paddingBottom="10dp" 
        android:paddingLeft="15dp" 
        android:paddingRight="15dp" 
        android:textColor="@color/link" /> 
       <com.evolustudios.askin.askin.src.Utils.FeedImageView 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:id="@+id/feedImage1_alternate" 
        android:background="#80FFFFFF" 
        android:scaleType="fitXY" 
        android:visibility="visible" /> 
      </LinearLayout> 
     </RelativeLayout> 


    </FrameLayout> 

</it.gmariotti.cardslib.library.view.CardViewNative>

feed_activity_alternate.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" android:layout_height="match_parent" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools"> 

<jp.co.recruit_lifestyle.android.widget.WaveSwipeRefreshLayout 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:id="@+id/feed_wave_swipe_layout_refresh_alternate"> 
    <android.support.v7.widget.RecyclerView 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:id="@+id/feeds_list_recycler_view" 
     android:layout_marginEnd="8dp" 
     android:layout_marginLeft="8dp" 
     android:scrollbars="vertical" 
     tools:listitem="@layout/feed_item_list_new"> 
    </android.support.v7.widget.RecyclerView> 

    <com.telenav.expandablepager.ExpandablePager 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:id="@+id/bottom_feed_container" 
     android:layout_gravity="bottom" 
     app:animation_duration="200" 
     app:collapsed_height="@dimen/header_height"/> 
</jp.co.recruit_lifestyle.android.widget.WaveSwipeRefreshLayout>

feed_page_alternative

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" android:layout_width="match_parent" 
android:layout_height="match_parent" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
xmlns:tools="http://schemas.android.com/tools" 
android:background="@color/pumice"> 

<include 
    layout="@layout/feed_header_layout"/> 

<LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="250sp" 
    android:layout_gravity="center_horizontal" 
    android:orientation="horizontal" 
    android:paddingTop="10dp" 
    android:id="@+id/feed_bottom_panel_first_container"> 

    <com.evolustudios.askin.askin.src.Utils.FeedImageView 
     android:layout_width="270sp" 
     android:layout_height="match_parent" 
     android:background="@color/edward" 
     android:id="@+id/feed_main_image_bottom_sheet" 
     android:scaleType="fitCenter"/> 

    <ScrollView 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:layout_gravity="center_vertical" 
     android:scrollbars="none"> 
     <ListView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:id="@+id/feed_extra_iamge_list_view_bootom_panel"> 
     </ListView> 
    </ScrollView> 

</LinearLayout> 
<LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="60dp" 
    android:id="@+id/feed_bottom_panel_second_container" 
    android:baselineAligned="false" 
    android:orientation="horizontal" 
    android:weightSum="5"> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <ImageView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:src="@drawable/ic_sentiment_very_satisfied_black_24dp" 
      android:scaleType="fitCenter" 
      android:padding="5dp"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <ImageView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:padding="5dp" 
      android:src="@drawable/ic_sentiment_satisfied_black_24dp" 
      android:scaleType="fitCenter"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <ImageView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:src="@drawable/ic_sentiment_neutral_black_24dp" 
      android:scaleType="fitCenter" 
      android:padding="5dp"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <ImageView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:src="@drawable/ic_sentiment_dissatisfied_black_24dp" 
      android:scaleType="fitCenter" 
      android:padding="5dp"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <ImageView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:src="@drawable/ic_sentiment_very_dissatisfied_black_24dp" 
      android:scaleType="fitCenter" 
      android:padding="5dp"/> 
    </RelativeLayout> 

</LinearLayout> 
<LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="30dp" 
    android:id="@+id/feed_bottom_panel_third_container" 
    android:baselineAligned="false" 
    android:orientation="horizontal" 
    android:weightSum="5"> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <TextView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:id="@+id/very_liked_number_bottom_panel" 
      android:text="100" 
      android:gravity="center" 
      android:textColor="@color/ming"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <TextView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:id="@+id/liked_number_bottom_panel" 
      android:text="100" 
      android:gravity="center" 
      android:textColor="@color/ming"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <TextView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:id="@+id/neutral_number_bottom_panel" 
      android:text="100" 
      android:gravity="center" 
      android:textColor="@color/ming"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <TextView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:id="@+id/not_liked_number_bottom_panel" 
      android:text="100" 
      android:gravity="center" 
      android:textColor="@color/ming"/> 
    </RelativeLayout> 
    <RelativeLayout 
     android:layout_width="0dp" 
     android:layout_height="match_parent" 
     android:layout_weight="1"> 
     <TextView 
      android:layout_width="match_parent" 
      android:layout_height="match_parent" 
      android:id="@+id/very_not_liked_number_bottom_panel" 
      android:text="100" 
      android:gravity="center" 
      android:textColor="@color/ming"/> 
    </RelativeLayout> 

</LinearLayout> 

<ScrollView 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:scrollbars="none" 
    android:paddingLeft="22dp" 
    android:paddingRight="22dp" 
    android:paddingTop="15dp" 
    android:paddingBottom="15dp"> 
    <com.evolustudios.askin.askin.src.customfonts.LoginTextView 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/body_bottom_panel_feed" 
     android:text="Body" 
     android:textSize="20dp"/> 
</ScrollView>

來源

2016-09-17 Thomas Scarecrow Maveric

可能重複[什麼是NullPointerException，以及如何解決它？]（http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-我修復它） –

是可能的，但我不能確定爲什麼它返回null！所以問題 –

你沒有發佈你的XML。這可能會讓你更明白爲什麼你的findViewById沒有找到你的ExpandablePager。 – chrisdowney

變化，

pager = (ExpandablePager) getActivity().findViewById(R.id.bottom_feed_container);

到

pager = (ExpandablePager) view.findViewById(R.id.bottom_feed_container);

而且改變，

final RecyclerView mRecyclerView = (RecyclerView) getActivity().findViewById(R.id.feeds_list_recycler_view);

到

final RecyclerView mRecyclerView = (RecyclerView) view.findViewById(R.id.feeds_list_recycler_view);

來源

2016-09-17 17:16:49

這個方法實際上解決了這個問題，但現在它顯示 - '試圖調用虛擬方法'void android.support.v7.widget.RecyclerView.setAdapter（android.support.v7.widget.RecyclerView $ Adapter）'在空對象引用' –

@Thomas請參閱編輯。 –

在空對象引用' –

陣列適配器返回null

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