android 购物车实现,Android Studio实现简单购物车功能 显示代码

好的，以下是一个简单的购物车功能的示例代码，包括商品列表、购物车列表和计算总价的代码。

1. 商品列表代码

public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ViewHolder> {

    private List<Product> productList;

    public ProductAdapter(List<Product> productList) {
        this.productList = productList;
    }

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

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Product product = productList.get(position);
        holder.tvName.setText(product.getName());
        holder.tvPrice.setText(String.valueOf(product.getPrice()));
        holder.btnAddToCart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Cart.getInstance().addProduct(product);
            }
        });
    }

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

    static class ViewHolder extends RecyclerView.ViewHolder {

        TextView tvName;
        TextView tvPrice;
        Button btnAddToCart;

        ViewHolder(View itemView) {
            super(itemView);
            tvName = itemView.findViewById(R.id.tv_name);
            tvPrice = itemView.findViewById(R.id.tv_price);
            btnAddToCart = itemView.findViewById(R.id.btn_add_to_cart);
        }
    }
}

2. 购物车列表代码

public class CartAdapter extends RecyclerView.Adapter<CartAdapter.ViewHolder> {

    private List<Product> productList;

    public CartAdapter(List<Product> productList) {
        this.productList = productList;
    }

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

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        Product product = productList.get(position);
        holder.tvName.setText(product.getName());
        holder.tvPrice.setText(String.valueOf(product.getPrice()));
        holder.tvQuantity.setText(String.valueOf(product.getQuantity()));
        holder.btnIncrease.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Cart.getInstance().addProduct(product);
                notifyDataSetChanged();
            }
        });
        holder.btnDecrease.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Cart.getInstance().removeProduct(product);
                notifyDataSetChanged();
            }
        });
    }

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

    static class ViewHolder extends RecyclerView.ViewHolder {

        TextView tvName;
        TextView tvPrice;
        TextView tvQuantity;
        Button btnIncrease;
        Button btnDecrease;

        ViewHolder(View itemView) {
            super(itemView);
            tvName = itemView.findViewById(R.id.tv_name);
            tvPrice = itemView.findViewById(R.id.tv_price);
            tvQuantity = itemView.findViewById(R.id.tv_quantity);
            btnIncrease = itemView.findViewById(R.id.btn_increase);
            btnDecrease = itemView.findViewById(R.id.btn_decrease);
        }
    }
}

3. 计算总价代码

public class Cart {

    private List<Product> productList;
    private static Cart instance;

    private Cart() {
        productList = new ArrayList<>();
    }

    public static synchronized Cart getInstance() {
        if (instance == null) {
            instance = new Cart();
        }
        return instance;
    }

    public void addProduct(Product product) {
        if (productList.contains(product)) {
            int index = productList.indexOf(product);
            Product p = productList.get(index);
            p.setQuantity(p.getQuantity() + 1);
        } else {
            product.setQuantity(1);
            productList.add(product);
        }
    }

    public void removeProduct(Product product) {
        if (productList.contains(product)) {
            int index = productList.indexOf(product);
            Product p = productList.get(index);
            if (p.getQuantity() == 1) {
                productList.remove(index);
            } else {
                p.setQuantity(p.getQuantity() - 1);
            }
        }
    }

    public double getTotalPrice() {
        double totalPrice = 0.0;
        for (Product product : productList) {
            totalPrice += product.getPrice() * product.getQuantity();
        }
        return totalPrice;
    }

    public List<Product> getProductList() {
        return productList;
    }

    public void clear() {
        productList.clear();
    }
}

以上是一个简单的购物车功能的示例代码，仅供参考。具体实现过程可以根据个人需求进行调整和改进。