价格错误更新

Question

我对购物车中单件商品的总价更新错误。如果我增加数量并减少数量，则会发生以下情况：

增加数量1=4,10；2=4,10；3=8,20；4=12,30；减少数量：从 4(16,30) 到 3 = 16,40；2 = 12,30；1=8,20；

但所有物品的总价格是正确的。

public class CartAdapter extends RecyclerView.Adapter<CartViewHolder> {

private List<Order> listData = new ArrayList<>();

private Cart cart;

public CartAdapter(List<Order> listData, Cart cart) {

    this.listData = listData;

    this.cart = cart;

}

@NonNull

@Override

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

    LayoutInflater inflater = LayoutInflater.from(cart);

    View itemView = inflater.inflate(R.layout.cart_layout, parent, false);

    return new CartViewHolder(itemView);

}

@Override

public void onBindViewHolder(@NonNull final CartViewHolder holder, final int position) {

    holder.btn_quantity.setNumber(listData.get(position).getQuantity());

    holder.btn_quantity.setOnValueChangeListener(new ElegantNumberButton.OnValueChangeListener() {

        @Override

        public void onValueChange(ElegantNumberButton view, int oldValue, int newValue) {

            Locale locale = new Locale("de", "DE");

            NumberFormat fmt = NumberFormat.getCurrencyInstance(locale);

            double price = (Double.parseDouble(listData.get(position).getPrice()))*(Double.parseDouble(listData.get(position).getQuantity()));

            //int price = (Integer.parseInt(listData.get(position).getPrice()))*(Integer.parseInt(listData.get(position).getQuantity()));

            holder.txt_price.setText(fmt.format(price));

            holder.txt_cart_name.setText(listData.get(position).getProductName());

        }

    });

Answer 1

可能，问题出在代码序列中，您应该输入以下代码：Order order = listData.get(position);order.setQuantity(String.valueOf(newValue));new Database(cart).updateCart(order);在开始：public void onValueChange(ElegantNumberButton view, int oldValue, int newValue) {&nbsp; // event listener code}这个块。我希望它有帮助:)