android - notifyItemChanged 方法不会在 recyclerview 中调用 onBindViewHolder

Question

我的代码如下所示:

public class PopularItemsAdapter extends RecyclerView.Adapter<PopularItemsAdapter.MyViewHolder>
        implements MyCartListener {

    private Context mContext;
    private List<FoodTruckItem> foodTruckItemList;
    private boolean isClickable = false;
    private OnItemClickListener listener;
    private List<FoodtruckInfo> foodtruckInfoList = new ArrayList<>();
    private List<FoodTruckItem> sessionItem = new ArrayList<>();
    private boolean isConflictResolved = false;
    public int position = -1;


    @Override
    public void itemUpdated(int quantity, String itemId) {
        for (int i = 0; i < foodTruckItemList.size(); i++) {
            if (itemId.equals(foodTruckItemList.get(i).getItemId())) {
                foodTruckItemList.get(i).setItemQuantityOrdered(quantity);
//                notifyDataSetChanged();
            }
        }
    }

    @Override
    public void itemRemoved(String itemId) {
        for (int j = 0; j < foodTruckItemList.size(); j++) {
            if (itemId.equals(foodTruckItemList.get(j).getItemId())) {
                foodTruckItemList.remove(j);
//                notifyDataSetChanged();
            }
        }
    }

    public void addConflictItem(int position) {
        isConflictResolved = true;
        notifyItemChanged(position);
    }

    public interface OnItemClickListener {
        void onItemClick(FoodTruckItem foodTruckItem, FoodtruckInfo foodtruckInfo);

        void showSnackBar(int items, boolean added, int position);

        void showRestaurentClosed();

        void showWarningDialog(int position);
    }


    public void addFoodInfo(List<FoodtruckInfo> foodtruckInfos) {
        foodtruckInfoList.addAll(foodtruckInfos);
    }


    public class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        public TextView itemName, foodPrice, addText, quantityText, addQuantity, removeQuantity;
        public ImageView itemImage, itemTag;
        public LinearLayout addLayout;

        public MyViewHolder(View view) {
            super(view);
            itemTag = (ImageView) view.findViewById(R.id.itemTag);
            itemImage = (ImageView) view.findViewById(R.id.itemImage);
            itemName = (TextView) view.findViewById(R.id.itemName);
            foodPrice = (TextView) view.findViewById(R.id.foodPrice);
            addText = (TextView) view.findViewById(R.id.addText);
            addLayout = (LinearLayout) view.findViewById(R.id.addLayout);
            quantityText = (TextView) view.findViewById(R.id.quantityText);
            addQuantity = (TextView) view.findViewById(R.id.addQuantity);
            removeQuantity = (TextView) view.findViewById(R.id.removeQuantity);
            view.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            FoodtruckInfo foodtruckInfo = new FoodtruckInfo();
            //passing the clicked position to the parent class
            for (FoodtruckInfo info : foodtruckInfoList) {
                if (info.getItemId().equals(foodTruckItemList.get(getAdapterPosition()).getItemId())) {
                    foodtruckInfo = info;
                }
            }
            listener.onItemClick(foodTruckItemList.get(getAdapterPosition()), foodtruckInfo);
        }
    }


    public PopularItemsAdapter(Context mContext, List<FoodTruckItem> foodTruckItemList, OnItemClickListener listener) {
        this.mContext = mContext;
        this.foodTruckItemList = foodTruckItemList;
        this.listener = listener;
        MyCart.getInstance().addListener(this);
    }

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

        return new MyViewHolder(itemView);
    }

    @Override
    public int getItemViewType(int position) {
        return position;
    }

    @Override
    public void onBindViewHolder(final MyViewHolder holder, final int position) {
        final FoodTruckItem foodTruckItem = foodTruckItemList.get(position);
        if (SessionManager.get(mContext).getFoodTruckItemList() != null) {
            sessionItem = SessionManager.get(mContext).getFoodTruckItemList();
            for (FoodTruckItem item : sessionItem) {
                if (item.getItemId().equals(foodTruckItem.getItemId())) {
//                    holder.itemTag.setText("MY FAVOURITE");
                    holder.itemTag.setImageDrawable(ContextCompat.getDrawable(mContext, R.drawable.ic_favorite));
                }
            }
        }

        holder.itemName.setText(foodTruckItem.getItemName());
//        holder.itemTag.setText(foodTruckItem.getSpecialTag());
        holder.foodPrice.setText("$" + String.valueOf(foodTruckItem.getItemPrice()));
        Picasso.Builder builder = new Picasso.Builder(mContext);
        builder.listener(new Picasso.Listener() {
            @Override
            public void onImageLoadFailed(Picasso picasso, Uri uri, Exception exception) {
                exception.printStackTrace();
            }
        });
        if (!TextUtils.isEmpty(foodTruckItem.getItemImg())) {
            builder.build().load(foodTruckItem.getItemImg()).into(holder.itemImage);
        }
        holder.addText.setOnClickListener(new View.OnClickListener() {
            FoodtruckInfo info = new FoodtruckInfo();

            @Override
            public void onClick(View v) {
                for (int l = 0; l < foodtruckInfoList.size(); l++) {
                    if (foodtruckInfoList.get(l).getItemId().equals(foodTruckItem.getItemId())) {
                        if (foodtruckInfoList.get(l).getOrderStatus() == 0) {
                            isClickable = true;
                        } else {
                            isClickable = false;
                        }
                    }
                }
                if (isClickable) {
                    String foodTruckId = null;
                    if (MyCart.getInstance().getFoodTruckId() != null) {
                        foodTruckId = MyCart.getInstance().getFoodTruckId();
                        if (!foodTruckId.equals(foodtruckInfoList.get(position).getFoodTruckId())) {
                            listener.showWarningDialog(position);
                        } else {
                            addItem(holder, position, foodTruckItem);
                        }
                    } else {
                        isConflictResolved = false;
                        addItem(holder, position, foodTruckItem);
                    }
                } else {
                    listener.showRestaurentClosed();
                }

                if (isConflictResolved) {
                    isConflictResolved = false;
                    addItem(holder, position, foodTruckItem);
                }
            }
        });

        holder.addQuantity.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int quantity = foodTruckItem.getItemQuantityOrdered();
                quantity += 1;
                holder.quantityText.setText(String.valueOf(quantity));
                MyCart.getInstance().updateQuantity(quantity, foodTruckItem.getItemId(), false);
            }
        });

        holder.removeQuantity.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int quantity = foodTruckItem.getItemQuantityOrdered();
                quantity -= 1;
                if (quantity == 0) {
                    MyCart.getInstance().removeItem(foodTruckItem.getItemId(), false);
                    holder.addLayout.setVisibility(View.INVISIBLE);
                    holder.addText.setVisibility(View.VISIBLE);
                    listener.showSnackBar(quantity, false, position);
                } else {
                    holder.quantityText.setText(String.valueOf(quantity));
                    MyCart.getInstance().updateQuantity(quantity, foodTruckItem.getItemId(), false);
                }
            }
        });
        setFontStyle(holder);
    }


    private void addItem(MyViewHolder holder, int position, FoodTruckItem foodTruckItem) {
        holder.addLayout.setVisibility(View.VISIBLE);
        holder.addText.setVisibility(View.INVISIBLE);
        foodTruckItem.setItemQuantityOrdered(1);
        holder.quantityText.setText(String.valueOf(1));
        MyCart.getInstance().addItem(foodTruckItem);
        MyCart.getInstance().setFoodTruckId(foodtruckInfoList.get(position).getFoodTruckId());
        listener.showSnackBar(MyCart.getInstance().getItemList(), true, position);

    }

    private void setFontStyle(MyViewHolder holder) {
        holder.itemName.setTypeface(Typeface.createFromAsset(mContext.getAssets(), Consts.montserrat_bold));
//        holder.itemTag.setTypeface(Typeface.createFromAsset(mContext.getAssets(), Consts.montserrat_bold));
        holder.foodPrice.setTypeface(Typeface.createFromAsset(mContext.getAssets(), Consts.montserrat_bold));
        holder.addText.setTypeface(Typeface.createFromAsset(mContext.getAssets(), Consts.montserrat_bold));
    }


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

这里 addConflictItem() 我写了 notifyItemChanged ，但不知何故它没有调用 onBindViewHolder ，所以应用程序中是否缺少任何内容？

Answer 1

我遇到了同样的问题，这对我有用，只需将这些行添加到您的 recyclerview 声明中，请参阅 this Asnswer

DefaultItemAnimator animator = new DefaultItemAnimator() {
    @Override
    public boolean canReuseUpdatedViewHolder(RecyclerView.ViewHolder viewHolder) {
        return true;
    }
}; 
mRecyclerView.setItemAnimator(animator);