Java 多个viewholder recyclerview上的强制转换异常

我在

DataListAdapter

中使用了多个viewholder。 每个支架都有一个适配器

我的适配器：

public class DataListAdapter extends BaseAdapter<HomeListItem> {
    private RecyclerView.RecycledViewPool pool;
    public static final int ADS = 10, DATA = 11, PIC = 13, QUE=14;



    public DataListAdapter(ArrayList<HomeListItem> dataList, AdapterListener<HomeListItem> listener) {
        this.dataList = dataList;
        this.listener = listener;
        pool = new RecyclerView.RecycledViewPool();
    }



    @Override
    public void onViewRecycled(@NonNull BaseViewHolder holder) {
        super.onViewRecycled(holder);
    }

    @NonNull
    @Override
    public BaseViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        if (viewType == ADS){
            return new ADSDataHolder(LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.item_home_ads, parent, false));
        }else if (viewType == PIC) {
            return new PictureHolder(LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.list_item_home, parent, false));
        }else if (viewType == QUE) {
            return new QuestionHolder(LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.list_item_home, parent, false));
        }else
            return new DataHolder(LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.list_item_home, parent, false));

    }

    @Override
    public int getItemViewType(int position) {

        if (dataList.get(position).getType() == ContentType.ADS)
            return ADS;
        if (dataList.get(position).getType() == ContentType.GALLERY)
            return PIC;
        if (dataList.get(position).getType() == ContentType.LIBS )
            return DATA;

        return QUE;
    }

    @Override
    public void onBindViewHolder(@NonNull BaseViewHolder holder, int position) {
             if (holder instanceof DataHolder){
                 ((DataHolder) holder).bind(dataList.get(position));
            } else if (holder instanceof ADSDataHolder) {
                ((ADSDataHolder) holder).bind(dataList.get(position));
            } else if (holder instanceof PictureHolder) {
                ((PictureHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof QuestionHolder) {
                ((QuestionHolder) holder).bind(dataList.get(position));
            }
    }

    class ADSDataHolder extends BaseViewHolder {
        ...
    }

    class PictureHolder extends BaseViewHolder {
         ...
    }


    class QuestionHolder extends BaseViewHolder{
        private RecyclerView recyclerView;
        private TextView title;
        private View more;
        public QuestionHolder(View itemView) {
            super(itemView);
            setType(QUE);

            more = itemView.findViewById(R.id.more);
            title = itemView.findViewById(R.id.title);
            recyclerView = itemView.findViewById(R.id.recyclerView);
            recyclerView.setLayoutManager(new LinearLayoutManager(itemView.getContext(),RecyclerView.HORIZONTAL,false));
            recyclerView.hasFixedSize();
            recyclerView.setRecycledViewPool(pool);
        }
        public void bind(HomeListItem data) {
            Collections.reverse(data.getData());
            title.setText(data.getType().getVisibleName());
            HomeQuestionAdapter adapter = new HomeQuestionAdapter((ArrayList<MainPageItem>) (ArrayList<?>) data.getData(),
                    new AdapterListener<MainPageItem>() {
                        @Override
                        public void onItemClick(MainPageItem item) {
                            onListItemClick(itemView.getContext(), data.getType(), item.getItemId());
                        }
                    });
            recyclerView.setAdapter(adapter);
            more.setOnClickListener(v -> listener.onItemClick(data));
        }
    }
    class DataHolder extends BaseViewHolder {

        private RecyclerView recyclerView;
        private TextView title;
        private View more;

        DataHolder(View itemView) {
            super(itemView);
            setType(DATA);

            more = itemView.findViewById(R.id.more);
            title = itemView.findViewById(R.id.title);
            recyclerView = itemView.findViewById(R.id.recyclerView);
            recyclerView.setLayoutManager(new LinearLayoutManager(itemView.getContext(),
                    LinearLayoutManager.HORIZONTAL, true));
            recyclerView.hasFixedSize();
            recyclerView.setRecycledViewPool(pool);
        }

        public void bind(HomeListItem data) {
            Collections.reverse(data.getData());
            title.setText(data.getType().getVisibleName());
            SmallItemAdapter adapter = new SmallItemAdapter((ArrayList<MainPageItem>)
                    (ArrayList<?>) data.getData(),
                    new AdapterListener<MainPageItem>() {
                        @Override
                        public void onItemClick(MainPageItem item) {
                            onListItemClick(itemView.getContext(), data.getType(), item.getItemId());
                        }
                    });
            recyclerView.setAdapter(adapter);
            recyclerView.scrollToPosition(data.getData().size() - 1);
            more.setOnClickListener(v -> listener.onItemClick(data));
        }
    }

    private void onListItemClick(Context context, ContentType contentType, long id) {
         // click
    }


}

当我滚动recyclerview时，会显示一个错误

我的错误：

:00:26.247 4194-4194/ir.hnfadak.shahidezendeh E/PushPole:Exception caught 
    java.lang.ClassCastException: ir.hfadak.fadakmedia.UI.Main.Home.Picture.SmallItemAdapter$DataHolder cannot be cast to ir.hfadak.fadakmedia.UI.Main.Question.HomeQuestionAdapter$DataQueHolder
        at ir.hfadak.fadakmedia.UI.Main.Question.HomeQuestionAdapter.onBindViewHolder(HomeQuestionAdapter.java:31)
        at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:7065)
        at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:7107)
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:6012)
        at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6279)
        at androidx.recyclerview.widget.GapWorker.prefetchPositionWithDeadline(GapWorker.java:288)
        at androidx.recyclerview.widget.GapWorker.flushTaskWithDeadline(GapWorker.java:345)
        at androidx.recyclerview.widget.GapWorker.flushTasksWithDeadline(GapWorker.java:361)
        at androidx.recyclerview.widget.GapWorker.prefetch(GapWorker.java:368)
        at androidx.recyclerview.widget.GapWorker.run(GapWorker.java:399)
        at android.os.Handler.handleCallback(Handler.java:754)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:163)
        at android.app.ActivityThread.main(ActivityThread.java:6238)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:933)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)

还有我的家

public class HomeQuestionAdapter extends RecyclerView.Adapter<HomeQuestionAdapter.DataQueHolder> {

    private RoundedCorners roundedCorners;
    protected List<MainPageItem> dataList;
    protected final int DATA_TYPE = 1;
    protected boolean isLoading = false, isMoreDataAvailable = false;
    protected AdapterListener<MainPageItem> listener;


    public HomeQuestionAdapter(ArrayList<MainPageItem> dataList, AdapterListener<MainPageItem> listener) {
        this.dataList = dataList;
        this.listener = listener;
        roundedCorners = new RoundedCorners(16);
    }



    @Override
    public int getItemViewType(int position) {
        if (dataList.get(position) == null)
            return -1;
        else return DATA_TYPE;
    }

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

    public void setMoreDataAvailable(boolean isMoreDataAvailable) {
        this.isMoreDataAvailable = isMoreDataAvailable;
    }

    public void removeLoadingItem() {
        if (dataList.size() > 0 && dataList.get(dataList.size() - 1) == null) {
            dataList.remove(dataList.size() - 1);
            notifyItemRemoved(dataList.size() - 1);
        }
    }

    public void notifyDataChanged() {
        isLoading = false;
        notifyDataSetChanged();
    }





    @NonNull
    @Override
    public HomeQuestionAdapter.DataQueHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            return new DataQueHolder(LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.item_list_simple_question, parent, false));
    }


    @Override
    public void onBindViewHolder(@NonNull HomeQuestionAdapter.DataQueHolder holder, int position) {
        if (!isLoading && isMoreDataAvailable && position >= getItemCount() - 1) {
            isLoading = true;
            listener.onLoadMore();
        } else {
             holder.bind(dataList.get(position));
        }
    }


    class DataQueHolder extends RecyclerView.ViewHolder {
        private ImageView image;
        private ImageView share,faivorid;
        private TextView question,answer,view;

        DataQueHolder(View itemView) {
            super(itemView);
            image = itemView.findViewById(R.id.imageQue);
            question = itemView.findViewById(R.id.titleQue);
            answer = itemView.findViewById(R.id.answerQue);
            share = itemView.findViewById(R.id.share);
            faivorid = itemView.findViewById(R.id.favorite);
            view = itemView.findViewById(R.id.viewtxt);

        }

        void bind(MainPageItem data) {
            Glide.with(itemView)
                    .load(data.getItemSmallImageAddress())
                    .apply(bitmapTransform(roundedCorners))
                    .apply(new RequestOptions().error(R.drawable.img_list_def)
                            .placeholder(R.drawable.img_list_def))
                    .into(image);
            question.setText(data.getItemTitle());
            answer.setText(data.getItemDescription());
            share.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    ContextUtil.share(itemView.getContext(),
                            data.getItemTitle() + "\n\n"
                                    + data.getItemDescription() + "\n\n"
                                    + data.getItemSmallImageAddress());
                }
            });


            itemView.setOnClickListener(v -> listener.onItemClick(data));
        }
    }
}

公共类HomeQuestionAdapter扩展了RecyclerView.Adapter{
私人圆角圆角；
受保护列表数据列表；
受保护的最终整数数据类型=1；
受保护的布尔isLoading=false，isMoreDataAvailable=false；
受保护的适配器侦听器；
公共HomeQuestionAdapter（ArrayList数据列表、AdapterListener侦听器）{
this.dataList=dataList；
this.listener=listener；
圆角=新圆角（16）；
}
@凌驾
public int getItemViewType（int位置）{
if（dataList.get（position）==null）
返回-1；
否则返回数据类型；
}
@凌驾
public int getItemCount（）{
返回dataList.size（）；
}
public void setMoreDataAvailable（布尔值isMoreDataAvailable）{
this.isMoreDataAvailable=isMoreDataAvailable；
}
公共void removeLoadingItem（）{
if（dataList.size（）>0&&dataList.get（dataList.size（）-1）==null）{
dataList.remove（dataList.size（）-1）；
notifyItemRemoved（dataList.size（）-1）；
}
}
public void notifyDataChanged（）{
isLoading=false；
notifyDataSetChanged（）；
}
@非空
@凌驾
public HomeQuestionAdapter.DataQueHolder onCreateViewHolder（@NonNull ViewGroup父级，int viewType）{
返回新的DataQueHolder（LayoutInflater.from（parent.getContext（））
.充气（R.layout.item_list_simple_question，parent，false））；
}
@凌驾
public void onBindViewHolder（@NonNull HomeQuestionAdapter.DataQueHolder，int位置）{
如果（！isLoading&&isMoreDataAvailable&&position>=getItemCount（）-1）{
isLoading=true；
listener.onLoadMore（）；
}否则{
holder.bind（dataList.get（position））；
}
}
类DataQueHolder扩展了RecyclerView.ViewHolder{
私有图像查看图像；
私有ImageView共享，faivorid；
私有文本查看问题、答案、视图；
DataQueHolder（查看项目视图）{
超级（项目视图）；
image=itemView.findviewbyd（R.id.imageQue）；
问题=itemviewbyd.findviewbyd（R.id.titleQue）；
答案=itemviewbyd（R.id.answerQue）；
share=itemView.findviewbyd（R.id.share）；
faivorid=itemView.findviewbyd（R.id.favorite）；
view=itemView.findviewbyd（R.id.viewtxt）；
}
无效绑定（MainPageItem数据）{
使用（项目视图）滑动
.load（data.getItemSmallImageAddress（））
.apply（位图变换（圆角））
.apply（新请求选项（）.error（R.drawable.img_list_def）
.占位符（R.drawable.img_list_def））
.进入（图像）；
question.setText（data.getItemTitle（））；
set文本（data.getItemDescription（））；
share.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
ContextUtil.share（itemView.getContext（），
data.getItemTitle（）+“\n\n”
+data.getItemDescription（）+“\n\n”
+data.getItemSmallImageAddress（））；
}
});
setOnClickListener（v->listener.onItemClick（数据））；
}
}
}

---

代码哪里出错？

您的类型正在将super类的实例转换为导致此错误的sub类的引用

而是创建如下内容：-

public void onBindViewHolder(@NonNull BaseViewHolder holder, int position) {
             if (holder instanceof DataQueHolder){
                 ((DataQueHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof DataHolder){
                 ((DataHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof ADSDataHolder) {
                ((ADSDataHolder) holder).bind(dataList.get(position));
            } else if (holder instanceof PictureHolder) {
                ((PictureHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof QuestionHolder) {
                ((QuestionHolder) holder).bind(dataList.get(position));
            }
    }

---

请从

DataListAdapter

recyclerView.setRecycledViewPool(pool);

---

它对我有效。

崩溃似乎来自HomeQuestionAdapter，但您发布的适配器是DataListAdapter。是相同的代码吗？添加了HomeQuestionAdapter，但我认为问题来自DataListAdapter

public void onBindViewHolder(@NonNull BaseViewHolder holder, int position) {
             if (holder instanceof DataQueHolder){
                 ((DataQueHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof DataHolder){
                 ((DataHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof ADSDataHolder) {
                ((ADSDataHolder) holder).bind(dataList.get(position));
            } else if (holder instanceof PictureHolder) {
                ((PictureHolder) holder).bind(dataList.get(position));
            }else if (holder instanceof QuestionHolder) {
                ((QuestionHolder) holder).bind(dataList.get(position));
            }
    }

recyclerView.setRecycledViewPool(pool);