應用程序嘗試使用其他信息填充活動b時崩潰

Question

我已經設置了應用程序，因此當我點擊Recycler上的視圖時正常查看電影圖像轉換到活動B.現在，當我嘗試填充關於活動B中的對象（如情節等）我得到一個錯誤，說我在onBindViewHolder中有null。我必須缺少一些東西，因爲我以前設置應用程序的方式（一張卡上的所有信息）所有內容都被正確查詢並顯示。這一切都開始發生時，我決定改變並將信息發送到活動B.

這裏是適配器

public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MyViewHolder> { 

private List<MovieData> moviesList; 
private Context context; 
private ClickListener clickListener; 
ImageLoader imageLoader = AppController.getInstance().getImageLoader(); 

public MoviesAdapter(Context context, List<MovieData> moviesList) { 
    this.moviesList = moviesList; 
    this.context = context; 
} 

public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { 
    public TextView title, plot, releaseDate, rating; 
    public ImageView thumb; 
    public NetworkImageView moviePic; 

    public MyViewHolder(View view) { 
     super(view); 
     view.setOnClickListener(this); 
     title = (TextView) view.findViewById(R.id.name); 
     plot = (TextView) view.findViewById(R.id.plot); 
     releaseDate = (TextView) view.findViewById(R.id.releaseDate); 
     rating = (TextView) view.findViewById(R.id.rating); 
     thumb = (ImageView) view.findViewById(R.id.thumb); 
     moviePic = (NetworkImageView) view.findViewById(R.id.profilePic); 
    } 

    @Override 
    public void onClick(View v) { 

     //context.startActivity(new Intent(context,DisplayActivity.class)); 
     if (clickListener != null) { 
      clickListener.itemClicked(v, getAdapterPosition()); 

      } 
     } 
    } 


@Override 
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    View itemView = LayoutInflater.from(parent.getContext()) 
      .inflate(R.layout.movie_row, parent, false); 

    return new MyViewHolder(itemView); 
} 

@Override 
public void onBindViewHolder(MyViewHolder holder, int position) { 
    MovieData movie = moviesList.get(position); 
    holder.title.setText(movie.getTitle()); 
    holder.plot.setText(movie.getPlot()); 
    holder.releaseDate.setText(movie.getReleaseDate()); 

    holder.rating.setText(movie.getRating()); 
    Float nRating = Float.parseFloat(holder.rating.getText().toString()); 

    if (nRating > 6.5) { 
     holder.thumb.setImageResource(R.drawable.ic_thumbs_up); 
    } else { 
     holder.thumb.setImageResource(R.drawable.ic_thumbdown); 
    } 



    holder.moviePic.setImageUrl(movie.getImage(), imageLoader); 

} 



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


//Interface and method to help with clicks 
public interface ClickListener { 

    void itemClicked(View view, int position); 
} 

public void setClickListener(ClickListener clickListener) { 
    this.clickListener = clickListener; 
} 

下面是在MainActivity

public class MainActivity extends AppCompatActivity implements MoviesAdapter.ClickListener { 

private static final String TAG = MainActivity.class.getSimpleName(); 

static final int SETTINGS_INTENT_REPLY = 1; 

private MoviesAdapter mAdapter; 
private List<MovieData> mData = new ArrayList<>(); 
private RecyclerView recyclerView; 
private GridLayoutManager gridLayoutManager; 



@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    //check Sdk Level 
    setContentView(R.layout.activity_main); 

    recyclerView = (RecyclerView) findViewById(R.id.recycler_view); 

    mAdapter = new MoviesAdapter(this, mData); 
    mAdapter.setClickListener(this); 
    gridLayoutManager = new GridLayoutManager(this,2); 
    recyclerView.setLayoutManager(gridLayoutManager); 
    recyclerView.setItemAnimator(new DefaultItemAnimator()); 
    recyclerView.setAdapter(mAdapter); 

    refreshMovie(); 

} 



@Override 
public void onActivityResult(int settingsRequestCode, int settingsResultcode, Intent resultData) { 
    super.onActivityResult(settingsRequestCode, settingsResultcode, resultData); 

    if (settingsRequestCode == SETTINGS_INTENT_REPLY) { 
     refreshMovie(); 
    } 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    MenuInflater inflater = getMenuInflater(); 
    inflater.inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 

    if (id == R.id.action_settings) { 
     Intent settingsIntent = new Intent(this, SettingsActivity.class); 
     startActivityForResult(settingsIntent, SETTINGS_INTENT_REPLY); 
     return true; 
    } 

    return super.onOptionsItemSelected(item); 
} 





public void refreshMovie() { 

    // Get a reference to the ConnectivityManager to check state of network connectivity 
    ConnectivityManager connMgr = (ConnectivityManager) 
      this.getSystemService(Context.CONNECTIVITY_SERVICE); 

    // Get details on the currently active default data network 
    NetworkInfo networkInfo = connMgr.getActiveNetworkInfo(); 

    // If there is a network connection, fetch data 
    if (networkInfo != null && networkInfo.isConnected()) { 


     mData.clear(); 

     networkCall(); 

    } else { 

     mData.clear(); 

     Snackbar snackbar = Snackbar 
       .make(recyclerView, "Network Error", Snackbar.LENGTH_INDEFINITE) 
       .setAction("Retry", new View.OnClickListener() { 
        @Override 
        public void onClick(View view) { 
         refreshMovie(); 
        } 
       }); 

     snackbar.show(); 
    } 
} 

/** 
* Parsing json reponse and passing the data to feed view list adapter 
*/ 
public void parseJsonFeed(JSONObject response) { 

    final String POSTER_BEGIN_URL = "http://image.tmdb.org/t/p/w500/"; 
    try { 
     JSONArray feedArray = response.getJSONArray("results"); 

     for (int i = 0; i < feedArray.length(); i++) { 
      JSONObject feedObj = (JSONObject) feedArray.get(i); 

      MovieData item = new MovieData(); 

      item.setTitle(feedObj.getString("original_title")); 

      // Image might be null sometimes 
      String image = feedObj.isNull("poster_path") ? null : feedObj 
        .getString("poster_path"); 
      String POSTER_URL = POSTER_BEGIN_URL + image; 
      item.setImage(POSTER_URL); 
      item.setPlot(feedObj.getString("overview")); 
      item.setRating(feedObj.getString("vote_average")); 
      item.setReleaseDate(feedObj.getString("release_date")); 

      mData.add(item); 
     } 

     // notify data changes to list adapater 
     mAdapter.notifyDataSetChanged(); 
    } catch (JSONException e) { 
     e.printStackTrace(); 
    } 
} 

public void networkCall() { 

    // We first check for cached request 
    Cache cache = AppController.getInstance().getRequestQueue().getCache(); 

    String order; 

    SharedPreferences sharedPrefs = 
      PreferenceManager.getDefaultSharedPreferences(this); 
    String orderType = sharedPrefs.getString(
      getString(R.string.pref_order_key), 
      getString(R.string.pref_most_popular)); 

    if (orderType.equals(getString(R.string.pref_top_rated))) { 
     order = "top_rated"; 
    } else { 
     order = "popular"; 
    } 

    String URL_FEED = "https://api.themoviedb.org/3/movie/" + order + "?api_key=" + BuildConfig.OPEN_MOVIE_API_KEY; 

    Cache.Entry entry = cache.get(URL_FEED); 
    if (entry != null) { 
     // fetch the data from cache 
     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 { 
     // making fresh volley request and getting json 
     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()); 
      } 
     }); 

     // Adding request to volley request queue 
     AppController.getInstance().addToRequestQueue(jsonReq); 

    } 

} 

@Override 
public void itemClicked(View view, int position) { 

    view.setTransitionName("mImage"); 

    MovieData movie = mData.get(position); 


    Intent intent = new Intent(this, DisplayActivity.class); 

    intent.putExtra("MoviePoster", movie.getImage()); 
    intent.putExtra("Title", movie.getTitle()); 
    intent.putExtra("rDate", movie.getReleaseDate()); 
    intent.putExtra("plot", movie.getPlot()); 
    intent.putExtra("rating", movie.getRating()); 


    ActivityOptionsCompat optionsCompat = ActivityOptionsCompat.makeSceneTransitionAnimation(this,view, view.getTransitionName()); 



    getApplicationContext().startActivity(intent,optionsCompat.toBundle()); 

} 

}

這裏活動B

public class DisplayActivity extends AppCompatActivity { 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_display); 

    ImageLoader imageLoader = AppController.getInstance().getImageLoader(); 

    TextView nTitle = (TextView) findViewById(R.id.name); 

    TextView nDate = (TextView) findViewById(R.id.releaseDate); 

    TextView nRating = (TextView) findViewById(R.id.rating); 

    TextView nPlot = (TextView) findViewById(R.id.plot); 


    NetworkImageView nProfilePic = (NetworkImageView) findViewById(R.id.profilePic); 



    // The detail Activity called via intent. Inspect the intent for data. 
    Bundle bundle = getIntent().getExtras(); 

    if (bundle != null) { 


     //intent 
     String movieImage = bundle.getString("MoviePoster"); 

     //intent 
     String movieName = bundle.getString("title"); 

     //intent 
     String movieDate = bundle.getString("rDate"); 

     //intent 
     String movieRating = bundle.getString("rating"); 

     //intent 
     String moviePlot = bundle.getString("plot"); 

     //set views 
     nProfilePic.setImageUrl(movieImage, imageLoader); 

     nTitle.setText(movieName); 

     nDate.setText(movieDate); 

     nRating.setText(movieRating); 

     nPlot.setText(moviePlot); 


    } 
} 

}

這裏是logcat的

04-12 14:01:22.349 23413-23413/com.app.sparkimagination.moviesmoviesmovies E/AndroidRuntime: FATAL EXCEPTION: main 
                         Process: com.app.sparkimagination.moviesmoviesmovies, PID: 23413 
                         java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference 
                          at adapter.MoviesAdapter.onBindViewHolder(MoviesAdapter.java:78) 
                          at adapter.MoviesAdapter.onBindViewHolder(MoviesAdapter.java:27) 
                          at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6356) 
                          at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6389) 
                          at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5335) 
                          at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5598) 
                          at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5440) 
                          at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5436) 
                          at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2224) 
                          at android.support.v7.widget.GridLayoutManager.layoutChunk(GridLayoutManager.java:556) 
                          at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1511) 
                          at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:595) 
                          at android.support.v7.widget.GridLayoutManager.onLayoutChildren(GridLayoutManager.java:170) 
                          at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3583) 
                          at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3312) 
                          at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3844) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
                          at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
                          at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.support.v7.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:437) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
                          at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743) 
                          at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586) 
                          at android.widget.LinearLayout.onLayout(LinearLayout.java:1495) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336) 
                          at android.widget.FrameLayout.onLayout(FrameLayout.java:273) 
                          at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2678) 
                          at android.view.View.layout(View.java:16630) 
                          at android.view.ViewGroup.layout(ViewGroup.java:5437) 
                          at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2171) 
                          at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1931) 
                          at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107) 
                          at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013) 
                          at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858) 
                          at android.view.Choreographer.doCallbacks(Choreographer.java:670) 
                          at android.view.Choreographer.doFrame(Choreographer.java:606) 
                          at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844) 
                          at android.os.Handler.handleCallback(Handler.java:739) 
                          at android.os.Handler.dispatchMessage(Handler.java:95) 
                          at android.os.Looper.loop(Looper.java:148) 
                          at android.app.ActivityThread.main(ActivityThr 

在先進的感謝

movie_row注意保持器中的所有其他觀點都在activity_display XML

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
xmlns:tools="http://schemas.android.com/tools" 
android:orientation="vertical" 
android:tag="cards main container"> 

<android.support.v7.widget.CardView 
    android:id="@+id/card_view" 
    xmlns:card_view="http://schemas.android.com/apk/res-auto" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    card_view:cardCornerRadius="2dp" 
    card_view:cardElevation="5dp" 
    card_view:cardUseCompatPadding="true"> 

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

     <com.android.volley.toolbox.NetworkImageView 
      android:id="@+id/profilePic" 
      android:transitionName="@string/transition_string" 
      android:layout_width="0dp" 
      android:layout_height="wrap_content" 
      android:layout_margin="5dp" 
      android:layout_weight="1" 
      /> 

    </LinearLayout> 

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

顯示XML所有的信息都是

ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:orientation="vertical" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:weightSum="1" 
tools:context=".DisplayActivity"> 

<LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical"> 

    <com.android.volley.toolbox.NetworkImageView 
     android:id="@+id/profilePic" 
     android:layout_width="match_parent" 
     android:layout_height="262dp" 
     android:scaleType="fitCenter" 
     android:transitionName="@string/transition_string" /> 

    <TextView 
     android:id="@+id/name" 
     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:weightSum="2"> 

     <ImageView 
      android:id="@+id/thumb" 
      android:layout_width="0dp" 
      android:layout_height="75dp" 
      android:layout_weight="1" 
      tools:src="@drawable/ic_thumbs_up" 
      /> 

     <TextView 
      android:id="@+id/rating" 
      android:layout_width="0dp" 
      android:layout_height="wrap_content" 
      android:layout_gravity="center" 
      android:textAlignment="center" 
      android:textSize="30dp" 
      android:layout_weight="1" 
      tools:text="9.0"/> 


    </LinearLayout> 

    <TextView 
     android:id="@+id/plot" 
     android:layout_width="match_parent" 
     android:layout_height="173dp" /> 

    <TextView 
     android:id="@+id/releaseDate" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" /> 


</LinearLayout> 

Answer 1

這裏的問題是，是，MyViewHolder類和onBindViewHolder()方法指的是，並呼籲觀點不屬於在movie_row XML的方法。例如，試圖找到R.id.plot，然後在onBindViewholder()嘗試呼叫holder.plot.setText()。在您的movie_row中沒有帶有id圖的TextView，因此您將收到NullPointerException和崩潰。

大概你以前確實在那裏有其他的意見，然後當你創建第二個活動時刪除它們。

解決這個問題的兩個主要選擇是要麼包括您想要在movie_row.xml中引用的所有視圖，如果您確實希望它們顯示在RecyclerView中，或者如果它們不打算在那裏，則將它們從MyViewHolder類和onBindViewHolder()方法。