Android RecyclerView Adapter加载菜单仅显示空白屏问题求助

API 探路者

2026-9-27

问题描述

Adapter无法正常展示菜单，仅显示空白屏幕。此前存在代码未初始化的问题，完成初始化操作后代码可正常运行，但原本应展示菜单的页面目前仅显示黑屏。

FoodListAdapter代码

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

    private List<Foods> foodList;
    private  FoodListClickListener clickListener;

    public FoodListAdapter(List<Foods> foodList, FoodListClickListener clickListener) {
        this.foodList = foodList;
        this.clickListener = clickListener;
    }

    public void updateData(List<Foods> foodList) {
        this.foodList = foodList;
        notifyDataSetChanged();
    }

    @NonNull
    @Override
    public FoodListAdapter.MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view  = LayoutInflater.from(parent.getContext()).inflate(R.layout.menu_recycler_row, parent, false);
        return  new MyViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull FoodListAdapter.MyViewHolder holder, int position) {
        holder.menuName.setText(foodList.get(position).getName());
        holder.menuPrice.setText("Price: $"+foodList.get(position).getPrice());
        holder.addToCartButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Foods food  = foodList.get(position);
                food.setTotalInCart(1);
                clickListener.onAddToCartClick(food);
                holder.addMoreLayout.setVisibility(View.VISIBLE);
                holder.addToCartButton.setVisibility(View.GONE);
                holder.tvCount.setText(food.getTotalInCart()+"");
            }
        });
        holder.imageMinus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Foods food  = foodList.get(position);
                int total = food.getTotalInCart();
                total--;
                if(total > 0 ) {
                    food.setTotalInCart(total);
                    clickListener.onUpdateCartClick(food);
                    holder.tvCount.setText(total +"");
                } else {
                    holder.addMoreLayout.setVisibility(View.GONE);
                    holder.addToCartButton.setVisibility(View.VISIBLE);
                    food.setTotalInCart(total);
                    clickListener.onRemoveFromCartClick(food);
                }
            }
        });

        holder.imageAddOne.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Foods food  = foodList.get(position);
                int total = food.getTotalInCart();
                total++;
                if(total <= 10 ) {
                    food.setTotalInCart(total);
                    clickListener.onUpdateCartClick(food);
                    holder.tvCount.setText(total +"");
                }
            }
        });

        Glide.with(holder.thumbImage)
                .load(foodList.get(position).getUrl())
                .into(holder.thumbImage);
    }

    @Override
    public int getItemCount() {
       List<Foods> foodList =new ArrayList<>();
        return foodList.size();
    }

    static class MyViewHolder extends RecyclerView.ViewHolder {
        TextView  menuName;
        TextView  menuPrice;
        TextView  addToCartButton;
        ImageView thumbImage;
        ImageView imageMinus;
        ImageView imageAddOne;
        TextView  tvCount;
        LinearLayout addMoreLayout;

        public MyViewHolder(View view) {
            super(view);
            menuName = view.findViewById(R.id.menuName1);
            menuPrice = view.findViewById(R.id.menuPrice1);
            addToCartButton = view.findViewById(R.id.addToCartButton1);
            thumbImage = view.findViewById(R.id.thumbImage1);
            imageMinus = view.findViewById(R.id.imageMinus1);
            imageAddOne = view.findViewById(R.id.imageAddOne1);
            tvCount = view.findViewById(R.id.tvCount1);
            addMoreLayout  = view.findViewById(R.id.addMoreLayout1);
        }
    }

    public interface FoodListClickListener {
        void onAddToCartClick(Foods food);
        void onUpdateCartClick(Foods food);
        void onRemoveFromCartClick(Foods food);
    }
}

Food实体类代码

public class Foods implements Parcelable{
    private String name;
    private float price;
    private String url;
    private int totalInCart;

    public int getTotalInCart() { return totalInCart; }

    public void setTotalInCart(int totalInCart) {
        this.totalInCart = totalInCart;
    }

    protected Foods(Parcel in) {
        name = in.readString();
        price = in.readFloat();
        url = in.readString();
        totalInCart = in.readInt();
    }

    public static final Creator<Foods> CREATOR = new Creator<Foods>() {
        @Override
        public Foods createFromParcel(Parcel in) { return new Foods(in);
        }

        @Override
        public Foods[] newArray(int size) { return new Foods[size]; }
    };

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public float getPrice() {
        return price;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name);
        dest.writeFloat(price);
        dest.writeString(url);
        dest.writeInt(totalInCart);
    }
}

备用菜单JSON数据

"menus":{
     "Drinks": [
       {
        "Fresh Fruit Blends": ["Strawberry", "Strawberry Banana","Banana Smoothie","Mango","Papaya","Honeydew","Pineapple", "Avacado",
        "Cantaloupe","Strawberry Lime","Fruit Tea","Mangonada"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/freshfruit.png?alt=media&token=13915c20-0d40-4542-a74e-20c791b085c2"
      },
       {
        "100% Natural Juices": ["Orange Juice", "Watermelon", "Carrot", "Carrot Orange","Fresh Limeade","Nuoc Mat(Artichoke Tea"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/nmat100%25naturaljuice.png?alt=media&token=f264240d-1764-480e-8155-b4948b28c36f"
      },
       {
        "Sea Foam": ["Matcha", "Earl Grey", "Jasmine", "Oolong","Thai Tea","Thai Green", "Black Coffee"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/seafoam.png?alt=media&token=d0175366-3310-4569-bbde-5aa30abcf533"
      },
      {
        "Cream Tea": ["Matcha", "Cream Tea","Jasmine", "Thai Tea","Thai Green Tea", "Oolong Cream","Brown Sugar Milk","Taro Cream","Almond Cream", "Caramel Cream", "Chocolate Cream", "Coconut Cream",
        "Honeydew", "Hazelnut", "Oreo Cream Tea", "Peppermint Cream Tea", "Vanilla Cream"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/bsmCreamtea.png?alt=media&token=da1ab8df-4e49-4c02-9080-e1dbb7d5c310"
      },
      {
        "Flavored Tea": ["Jasmine Green Tea", "Passion Fruit", "Strawberry", "Mango","Peppermint", "Lime","Honey","Dried Plum",
        "Green Apple","Peach","Lychee","Winter Melon","Pomegranate"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/sbgtea.png?alt=media&token=b74b21cc-8f77-47f1-aeb9-f3ecf744de54"
      },
      {
        "Smoothie": ["Oreo Cookies & Cream","Taro","Coconut","Pina Colada","Blueberry w/ Ice-Cream","Almond","Red Bean",
        "Chocolate","Frozen Matcha Green Tea","Orange Dreamsicle","Vanilla"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/tarosmoothie.png?alt=media&token=7fb66ea0-560a-4196-a152-dd09b1229a8c"
      },
      {
        "Slurpy": ["Kiwi","Blueberry","Cherry","Grape","Green Apple", "Lychee","Passion Fruit","Peach"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/mangoslurpy.png?alt=media&token=07191718-3737-47e1-b2dd-26775fb61fc1"
      },
       {"Coffee": ["Ice-Cream","Frozen Vanilla Cappuccino","Frozen Mocha","Coffee Cream Tea","Cafe Sua Da","Caramel","Hazelnut","Vanilla","Peppermint","Hot Cocoa"],
        "price": 10.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/FVFCOFFEE.png?alt=media&token=3c6f2b6b-3536-490a-838b-1fe027398d54"
      }
     ],
    "Foods" : [
      {
        "name": "Popcorn Chicken",
        "price": 5.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/PopcornCkn.png?alt=media&token=a4112144-2e52-4237-b4a7-781bf0c676dc"
      },
       {
        "name": "Sweet Potato Fries",
        "price": 5.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/SweetPotato.png?alt=media&token=38e45dfc-e886-4f85-aa3e-d36bc051f6e1"
      },
      {
        "name": "Egg Rolls",
        "price": 5.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/Eggrolls.png?alt=media&token=221167d6-13b1-48e0-8527-12ee686ba452"
      },
      {
        "name": "Calamari",
        "price": 5.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/Calamari.png?alt=media&token=004a3bbb-48e9-4392-88ae-2760310ebb00"
      },
       {
        "name": "Fried Squid Balls",
        "price": 5.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/Squid.png?alt=media&token=634a516f-2d7e-4983-8afb-4c0073ae04e1"
      },
       {
        "name": "Crinkle Cut Fries",
        "price": 5.00,
        "url": "https://firebasestorage.googleapis.com/v0/b/kims-tea-house.appspot.com/o/CrinkleFries.png?alt=media&token=b2a20607-1cfd-405d-96e9-ec92a0512576"
      }
    ]
  }

修复方案

核心问题修复

当前getItemCount方法中局部变量覆盖了类成员变量，每次都返回空列表的长度0，导致RecyclerView认为没有数据可渲染，是黑屏的直接原因。直接修改getItemCount方法即可：

@Override
public int getItemCount() {
    // 返回成员变量foodList的长度，不要新建空列表
    return foodList == null ? 0 : foodList.size();
}

其他需排查的问题

检查Drinks分类的JSON解析逻辑：Drinks下的菜单项没有name字段，而是把分类名作为键，解析时需要把分类名赋值给Food类的name属性，否则Drinks列表的菜品名称会为空。
检查RecyclerView是否正确设置了LayoutManager，未设置LayoutManager的情况下RecyclerView不会渲染任何内容。
检查item布局menu_recycler_row的根布局高度不要设置为match_parent，否则单个item会占满全屏，看起来和空白效果一致。
初始化Adapter或调用updateData前，确认传入的foodList已经完成JSON解析，不为空。

内容的提问来源于stack exchange，提问作者rebel2theworld

Android RecyclerView Adapter加载菜单仅显示空白屏问题求助

FoodListAdapter代码 #

Food实体类代码 #

备用菜单JSON数据 #

核心问题修复 #

其他需排查的问题 #

FoodListAdapter代码

Food实体类代码

备用菜单JSON数据

核心问题修复

其他需排查的问题