RecyclerViewをNullPointerExceptionによって断片化して実装している間に

Question

RecyclerViewをフラグメント化して実装する際に、recyclerView.setAdapter（adapter）でNullPointerExceptionを実装しています。 QuestionScreen.javaで

- 助けてください。

Fragment- QuestionScreen.java

import android.os.Bundle; 
import android.app.Fragment; 
import android.support.v7.widget.LinearLayoutManager; 
import android.support.v7.widget.RecyclerView; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.TextView; 

import static com.example.activist.theactivistchallenge.R.layout.questionscreen; 

    public class QuestionScreen extends Fragment { 

    RecyclerView recyclerView; 



    public QuestionScreen() { 
     // Required empty public constructor 
    } 


    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View rootview = inflater.inflate(questionscreen, container, false); 
     recyclerView = (RecyclerView) rootview.findViewById(R.id.question_recycler_view); 

     RecyclerAdapter adapter = new RecyclerAdapter(getActivity()); 
     recyclerView.setAdapter(adapter); 
     recyclerView.setHasFixedSize(true); 
     recyclerView.setLayoutManager(new LinearLayoutManager(getActivity())); 

     return rootview; 
    } 

} 

RecyclerAdapter.java

package com.example.activist.theactivistchallenge; 

    import android.content.Context; 
    import android.support.v7.widget.RecyclerView; 
    import android.view.LayoutInflater; 
    import android.view.View; 
    import android.view.ViewGroup; 
    import android.widget.Toast; 

    public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerViewHolder> { 

    String [] name={"Androidwarriors","Stackoverflow","Developer Android","AndroidHive", 
      "Slidenerd","TheNewBoston","Truiton","HmkCode","JavaTpoint","Javapeper"}; 
    Context context; 
    LayoutInflater inflater; 
    public RecyclerAdapter(Context context) { 
     this.context=context; 
     inflater=LayoutInflater.from(context); 
    } 
    @Override 
    public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     View v=inflater.inflate(R.layout.questionscreen_list, parent, false); 

     RecyclerViewHolder viewHolder=new RecyclerViewHolder(v); 
     return viewHolder; 
    } 

    @Override 
    public void onBindViewHolder(RecyclerViewHolder holder, int position) { 

     holder.question_desc.setText(name[position]); 
    } 




    @Override 
    public int getItemCount() { 
     return name.length; 
    } 
} 

Answer 1

rootview.findViewById(R.id.question_recycler_view)ビューが見つからない場合はnullを返すことがあります。

ID R.id.question_recycler_viewのR.layout.questionscreenのビューがありますか？私はものではありません。