再次向上滚动后，带有 Glide 的 RecyclerView 导致 NullPointer
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【中文标题】再次向上滚动后，带有 Glide 的 RecyclerView 导致 NullPointer【英文标题】：RecyclerView with Glide causing NullPointer after scrolling up again 【发布时间】：2017-01-15 09:13:29 【问题描述】：这是我的适配器类：
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
View view = inflater.inflate(R.layout.container_accommodation,parent,false);
MyHolder holder = new MyHolder(view);
holder.setIsRecyclable(false);
return holder;
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position)
MyHolder myHolder= (MyHolder) holder;
Accommodation current = data.get(position);
Picasso.with(context).load("http://10.0.2.2:18180/AAFS/Accommodations/"+current.AccommoID+"/Accomm_Images/"+current.AccommoMainImage.ImageName)
.error(R.drawable.error)
.into(myHolder.imageView);
这是我尝试再次向上滚动时遇到的错误，向下滚动可以正常工作。
致命异常：主要 java.lang.NullPointerException 在 com.example.phuluso.aafs.AdapterAccommodation.onBindViewHolder(AdapterAccommodation.java:73) 在 android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5471) 在 android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5504) 在 android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4741) 在 android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4617) 在 android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1994) 在 android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1390) 在 android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1353) 在 android.support.v7.widget.LinearLayoutManager.scrollBy(LinearLayoutManager.java:1180) 在 android.support.v7.widget.LinearLayoutManager.scrollVerticallyBy(LinearLayoutManager.java:1031) 在 android.support.v7.widget.RecyclerView$ViewFlinger.run(RecyclerView.java:4061) 在 android.view.Choreographer$CallbackRecord.run(Choreographer.java:725) 在 android.view.Choreographer.doCallbacks(Choreographer.java:555) 在 android.view.Choreographer.doFrame(Choreographer.java:524) 在 android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711) 在 android.os.Handler.handleCallback(Handler.java:615) 在 android.os.Handler.dispatchMessage(Handler.java:92) 在 android.os.Looper.loop(Looper.java:137) 在 android.app.ActivityThread.main(ActivityThread.java:4944) 在 java.lang.reflect.Method.invokeNative(Native Method) 在 java.lang.reflect.Method.invoke(Method.java:511) 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805) 在 dalvik.system.NativeStart.main(Native Method)
任何帮助都会很棒。
谢谢。
【问题讨论】：
粘贴适配器类的完整代码。 发布您的完整适配器代码。错误日志不够 在下面添加了完整的代码 AdapterAccommodation.java 文件中的第 73 行是什么？ 【参考方案1】：public class AdapterAccommodation extends RecyclerView.Adapter<RecyclerView.ViewHolder> implements Filterable
private Context context;
private LayoutInflater inflater;
List<Accommodation> data = Collections.emptyList();
List<Accommodation> mStringFilterList;
ValueFilter valueFilter;
public AdapterAccommodation(Context context,List<Accommodation>data)
this.context = context;
inflater = LayoutInflater.from(context);
this.data = data;
mStringFilterList = data;
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, final int viewType)
View view = inflater.inflate(R.layout.container_accommodation,parent,false);
MyHolder holder = new MyHolder(view);
holder.setIsRecyclable(false);
return holder;
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position)
MyHolder myHolder= (MyHolder) holder;
Accommodation current = data.get(position);
myHolder.textAccommoName.setText(current.AccommoName);
myHolder.txtAddress.setText("Address: " + current.AccommoAddress.Street + ", " + current.AccommoAddress.Town + ", " + current.AccommoAddress.City);
myHolder.txtGenderAllowed.setText("Gender Accommodated: " + current.AccommoDetails.GenderAllowed );
myHolder.txtDistance.setText("Distance from nearest Campus: " + current.Distance + " km");
myHolder.textCapacity.setText("Capacity: " + current.Capacity);
myHolder.textNearestCampus.setText("Nearest Campus: "+ current.NearestCampus);
Picasso.with(context).load("http://192.168.42.197:18180/AAFS/Accommodations/"+current.AccommoID+"/Accomm_Images/"+current.AccommoMainImage.ImageName)
.error(R.drawable.error)
.into(myHolder.imageView);
myHolder.ratingBar.setRating(current.avgAccommoRating);
myHolder.ratingBar.setIsIndicator(true);
myHolder.btnAdditionalDetails.setOnClickListener( new View.OnClickListener()
@Override
public void onClick(View v)
Intent intent = new Intent(context,AccommodationAdditionalDetails.class);
intent.putExtra("EXTRA_AccommodationID",data.get(position).AccommoID);
intent.putExtra("EXTRA_AccommodationName",data.get(position).AccommoName);
intent.putExtra("EXTRA_AccommodationCapacity",data.get(position).Capacity);
intent.putExtra("EXTRA_AccommodationNearestCampus",data.get(position).NearestCampus);
intent.putExtra("EXTRA_AccommodationDistance",data.get(position).Distance);
intent.putExtra("EXTRA_AccommodationAccreditedStatus",data.get(position).AccredStatus);
intent.putExtra("EXTRA_AccommodationCity",data.get(position).AccommoAddress.City);
intent.putExtra("EXTRA_AccommodationPostalAddress",data.get(position).AccommoAddress.PostalCode);
intent.putExtra("EXTRA_LATITUDE",data.get(position).AccommoAddress.Lattitude);
intent.putExtra("EXTRA_LONGITUDE",data.get(position).AccommoAddress.Longitude);
intent.putExtra("EXTRA_NUM_SHARING",data.get( position ).AccommoDetails.NumTwoSharingRooms);
intent.putExtra("EXTRA_NUM_SINGLE",data.get(position).AccommoDetails.NumSingleRooms);
intent.putExtra("EXTRA_RENT_SINGLE",data.get(position).AccommoDetails.RentSingle);
intent.putExtra("EXTRA_RENT_SHARING",data.get(position).AccommoDetails.RentSharing);
intent.putExtra("EXTRA_WIFI",data.get(position).AccommoDetails.WiFi);
intent.putExtra("EXTRA_LIBRARY",data.get(position).AccommoDetails.DedicatedStudyArea);
intent.putExtra("EXTRA_GYM",data.get(position).AccommoDetails.Gym);
intent.putExtra("EXTRA_SECURITY_LEVEL",data.get(position).AccommoDetails.SecurityLevel);
intent.putExtra("EXTRA_PARKING_LOT",data.get(position).AccommoDetails.ParkingPort);
intent.putExtra("EXTRA_GENDER",data.get(position).AccommoDetails.GenderAllowed);
intent.putExtra("EXTRA_TRANSPORT",data.get(position).AccommoDetails.TransportShuttle);
intent.putExtra("EXTRA_WASHING_MACHINE",data.get(position).AccommoDetails.WashingMachine);
intent.putExtra("EXTRA_NUM_BATHROOM",data.get( position ).AccommoDetails.NumBathrooms);
intent.putExtra("EXTRA_CLEANING_SERVICE",data.get( position ).AccommoDetails.CleaningService);
context.startActivity(intent);
SharedPreferences settings = enter code herePreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = settings.edit();
editor.putString("ACCOMMO_LATITUDE",data.get(position).AccommoAddress.Lattitude );
editor.commit();
SharedPreferences setting1 = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor1 = settings.edit();
editor.putString("ACCOMMO_LONGITUDE",data.get(position).AccommoAddress.Longitude );
editor.commit();
);
@Override
public int getItemCount()
return data.size();
class MyHolder extends RecyclerView.ViewHolder
TextView textAccommoName;
// ImageView ivAccommodation;
TextView textCapacity;
TextView textNearestCampus;
TextView txtAddress;
TextView txtGenderAllowed;
TextView txtDistance;
Button btnAdditionalDetails;
RatingBar ratingBar;
ImageView imageView ;
public MyHolder(View itemView)
super(itemView);
textAccommoName = (TextView)itemView.findViewById(R.id.textAccommodationName);
txtAddress = (TextView)itemView.findViewById(R.id.txtAddress );
txtGenderAllowed = (TextView)itemView.findViewById( R.id.txtGenderAllowed );
txtDistance = (TextView)itemView.findViewById( R.id.textDistanceFromNearestCampus );
imageView = (ImageView)itemView. findViewById(R.id.imageview);
// ivAccommodation = (ImageView)itemView.findViewById(R.id.img);
textCapacity = (TextView)itemView.findViewById(R.id.textCapacity);
textNearestCampus = (TextView)itemView.findViewById(R.id.textNearestCampus);
btnAdditionalDetails = (Button)itemView.findViewById(R.id.btnAdditionalDetails);
ratingBar = (RatingBar)itemView.findViewById(R.id.ratingBar);
@Override
public Filter getFilter()
if (valueFilter == null)
valueFilter = new ValueFilter();
return valueFilter;
private class ValueFilter extends Filter
@Override
protected FilterResults performFiltering(CharSequence constraint)
FilterResults results = new FilterResults();
if (constraint != null && constraint.length() > 0)
ArrayList<Accommodation> filterList = new ArrayList<Accommodation>();
for (int i = 0; i < mStringFilterList.size(); i++)
if ( (mStringFilterList.get(i).AccommoName.toUpperCase() )
.contains(constraint.toString().toUpperCase()))
Accommodation accommodation = new Accommodation();
accommodation.AccommoName = mStringFilterList.get(i).AccommoName;
accommodation.AccommoDetails.GenderAllowed = mStringFilterList.get(i).AccommoDetails.GenderAllowed;
accommodation.AccommoAddress.Town = mStringFilterList.get(i).AccommoAddress.Town;
accommodation.AccommoAddress.City = mStringFilterList.get(i).AccommoAddress.City;
accommodation.Capacity = mStringFilterList.get(i).Capacity;
accommodation.Distance = mStringFilterList.get(i).Distance;
accommodation.AccommoAddress.Street = mStringFilterList.get(i).AccommoAddress.Street;
accommodation.NearestCampus = mStringFilterList.get(i).NearestCampus;
accommodation.avgAccommoRating = mStringFilterList.get(i).avgAccommoRating;
filterList.add(accommodation);
results.count = filterList.size();
results.values = filterList;
else
results.count = mStringFilterList.size();
results.values = mStringFilterList;
return results;
@Override
protected void publishResults(CharSequence constraint,
FilterResults results)
data = (ArrayList<Accommodation>) results.values;
notifyDataSetChanged();
【讨论】：
【参考方案2】：您是否覆盖了适配器中的 getItemCount 方法？
@Override
public int getItemCount()
return data.size();
onBindViewHolder(VH holder, int position) 方法似乎提供了无效的位置参数。因此，当您从数据集合中获取住宿时，它会返回 null。您使用什么类型的收藏品来保存住宿？
【讨论】：
住宿作为一种类型【参考方案3】：好的，现在我看到了您的适配器代码，我认为问题很可能出在您的过滤器实现上。尝试将您的 publishResults 方法更改为：
@Override
protected void publishResults(CharSequence constraint,
FilterResults results)
if(results.count > 0)
data.clear();
data.addAll(results.values);
notifyDataSetChanged();
else
notifyDataSetInvalidated();
已编辑 - NPE 在尝试访问其中一个住宿对象的 AccommoMainImage 属性时发生。
添加了一个空检查来解决问题：
if(current.AccommoMainImage != null)
Picasso.with(context).load("http://10.0.2.2:18180/AAFS/Accommodations/"+current.AccommoID+"/Accomm_Images/"+current.AccommoMainImage.ImageName) .error(R.drawable.error) .into(myHolder.imageView);
【讨论】：
好的，所以当前的住宿为空。我认为您的基础住宿集合（数据）被您的过滤器类的publishResults 方法或permformFiltering 方法弄乱了。您是否将更改应用到 publishResults 方法？
要么，要么其中一个住宿对象有一个空的 AccommoMainImage 属性，你应该添加一个空检查：if(current.AccommoMainImage != null) Picasso.with(context).load("http://10.0.2.2:18180/AAFS/Accommodations/"+current.AccommoID+"/Accomm_Images/"+current.AccommoMainImage.ImageName) .error(R.drawable.error) .into(myHolder.imageView);
谢谢这是正确的，我在列表中的最后一个 AccommoMainImage 是 null 看不到。非常感谢
没有问题的人，如果有机会，请给我的答案投赞成票
当然。我该怎么做？以上是关于再次向上滚动后，带有 Glide 的 RecyclerView 导致 NullPointer的主要内容，如果未能解决你的问题，请参考以下文章
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