Я пытаюсь реализовать вид ресайклера с множественным зрением, но я не получаю желаемый результат

Question

Проверьте мой код:

import android.content.Context; 
import android.content.Intent; 
import android.support.v7.widget.RecyclerView; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 

import org.w3c.dom.ls.LSException; 

import java.util.ArrayList; 
import java.util.Arrays; 

/** 
* Created by Ankit on 3/25/2016. 
*/ 
public class CustomAdapterRecyclerView extends RecyclerView.Adapter<RecyclerView.ViewHolder> { 
    Context context; 
    private ArrayList<String> questionsList; 
    LayoutInflater layoutInflater; 

    public CustomAdapterRecyclerView(Context context, ArrayList<String> questionsList) { 
     this.context = context; 
     this.questionsList = questionsList; 
     layoutInflater = LayoutInflater.from(context); 
    } 

    @Override 
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     switch (viewType) { 
      case 1: 
       final View view = layoutInflater.inflate(R.layout.recycler_view_list, parent, false); 
       MyViewHolder myViewHolder = new MyViewHolder(view, context); 
       return myViewHolder; 
     default: 
      final View view1 = layoutInflater.inflate(R.layout.single_item_in_list, parent, false); 
      MyExpandedViewHolder myExpandedViewHolder= new MyExpandedViewHolder(view1, context,new ArrayList<String>(Arrays.asList("A","Aa"))); 
      return myExpandedViewHolder; 
     } 
} 

    @Override 
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { 
     switch (holder.getItemViewType()) 
     { 
      case 1: 
       MyViewHolder vh = (MyViewHolder) holder; 
       vh.questionTitle.setText(questionsList.get(position)); 
       break; 
      default: 
       MyExpandedViewHolder viewHolder= (MyExpandedViewHolder) holder; 
       viewHolder.getListView(); 
     } 
    } 
/* 
    @Override 
    public void onBindViewHolder(RecyclerView.V holder, int position) { 
     holder.questionTitle.setText(questionsList.get(position)); 
    }*/ 

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

    @Override 
    public int getItemViewType(int position) { 
    if(position ==0|| position==1|| position==2) 
    { 
     return 0; 
    } 
     else 
     return 1; 
    } 

    public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { 
     TextView questionTitle; 
     private Context context; 

     public MyViewHolder(final View itemView, Context context) { 
      super(itemView); 
      this.context = context; 
      itemView.setOnClickListener(this); 
      questionTitle = (TextView) itemView.findViewById(R.id.question); 
      questionTitle.setOnClickListener(this); 
     } 

     @Override 
     public void onClick(View v) { 
      Toast.makeText(context, "" + getAdapterPosition() + questionTitle.getText().toString(), Toast.LENGTH_LONG).show(); 
      Log.d("TAG", "" + getAdapterPosition()); 
      Intent intent = new Intent(context, ProgramViewer.class); 
      intent.putExtra("titlePos",getAdapterPosition()); 
      intent.putExtra("title",questionTitle.getText().toString()); 
      context.startActivity(intent); 
     } 
    } 
    public class MyExpandedViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener 
    { 
     private Context context; 
     ListView listView; 
     public MyExpandedViewHolder(View itemView, Context context,ArrayList<String> mobileArray) { 
      super(itemView); 
      this.context = context; 
      ArrayAdapter adapter = new ArrayAdapter<String>(context, R.layout.expanded_list_inside_recycler_view, mobileArray); 
      listView= (ListView) itemView.findViewById(R.id.list_view); 
      listView.setAdapter(adapter); 
     } 
     public ListView getListView() 
     { 
      return this.listView; 
     } 
     @Override 
     public void onClick(View v) { 
     Toast.makeText(context,getAdapterPosition()+"",Toast.LENGTH_LONG).show(); 
     } 
    } 
} 

То, что я пытался сделать, это расширить RecyclerView элемента по щелчку, но сначала я должны реализовать просмотр ресайклеров и просмотр списка вместе. Я получаю NullPointerException. Пожалуйста, расскажите мне о проблеме в моем коде. Ответ был бы весьма признателен.

файл журнала:

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference 
at kole.technicalbird.CustomAdapterRecyclerView$MyExpandedViewHolder.<init>(CustomAdapterRecyclerView.java:113) 
at kole.technicalbird.CustomAdapterRecyclerView.onCreateViewHolder(CustomAdapterRecyclerView.java:43) 
at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:5476) 
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4701) 
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(

Layout File: single_item_in_list.xml

<?xml version="1.0" encoding="utf-8"?> 
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
        android:orientation="vertical" 
        android:layout_width="match_parent" 
        android:layout_height="match_parent"> 
    <TextView 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/textView" 
     android:text="a"/> 
    </LinearLayout> 


**recycler_view_list** 
<?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="wrap_content" 
    android:orientation="vertical"> 

    <LinearLayout 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:orientation="horizontal"> 

     <android.support.v7.widget.CardView 
      android:layout_width="wrap_content" 
      android:layout_height="wrap_content" 
      android:clickable="true" 
      android:elevation="8dp"> 

      <RelativeLayout 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content"> 

       <TextView 
        android:id="@+id/question" 
        android:layout_width="match_parent" 
        android:layout_height="wrap_content" 
        android:layout_centerVertical="true" 
        android:fontFamily="sans-serif" 
        android:text="ques" 
        android:padding="8dp" 
        android:layout_marginRight="32dp" 
        android:textSize="16dp" /> 

       <TextView 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:layout_alignParentRight="true" 
        android:layout_marginRight="8dp" 
        android:fontFamily="sans-serif" 
        android:layout_centerVertical="true" 
        android:padding="8dp" 
        android:text=">" /> 
      </RelativeLayout> 

     </android.support.v7.widget.CardView> 

    </LinearLayout> 
    <ImageView 
     android:src="@android:drawable/divider_horizontal_dark" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:scaleType="fitXY" 
     android:paddingLeft="5dp" 
     android:paddingRight="5dp" 
     android:paddingBottom="0.2dp" 
     android:paddingTop="0.2dp" /> 
</LinearLayout> 


<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
       android:orientation="vertical" 
       android:layout_width="match_parent" 
       android:layout_height="match_parent"> 
<ListView 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/list_view"> 
</ListView> 
</LinearLayout> 

expanded_list_inside_recycler_view

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
       android:orientation="vertical" 
       android:layout_width="match_parent" 
       android:layout_height="match_parent"> 
<ListView 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/list_view"> 
</ListView> 
</LinearLayout> 

Answer 1

Где ваш ListView в ваш единственный _item_in_list.xml. У вашего single_item_in_list.xml нет listview, поэтому, когда вы используете getListView(), listview имеет значение null. Я думаю, это и есть причина!