Question

在我的应用程序中，我从数据库中获取所有数据，并在回收者视图中显示。我想在另一个textview中显示该金额的总和。

customcartlist.java

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

private Context mCtx;
private List<Cart> cartList;
private int Price,Qty;
private String Total;

public CustomCartList(Context mCtx, List<Cart> cartList) {
    this.mCtx = mCtx;
    this.cartList = cartList;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(mCtx);
    View view = inflater.inflate(R.layout.custom_cart_list,null);
    return new ViewHolder(view);
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    Cart cart = cartList.get(position);

    Price = Integer.parseInt(cart.getPrice());
    Qty = Integer.parseInt(cart.getQty());
    Total = String.valueOf((Price*Qty)); // I want to show sum of this.

    holder.product.setText(cart.getProductName());
    holder.qty.setText(cart.getQty());
    holder.price.setText(Total);
}

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

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    TextView product,qty,price;
    Button wishlist,remove;

    public ViewHolder(View view) {
        super(view);
        product = (TextView) view.findViewById(R.id.PRODUCT);
        price = (TextView) view.findViewById(R.id.PRODUCT_PRICE);
        qty = (TextView) view.findViewById(R.id.QTY);

        wishlist = (Button) view.findViewById(R.id.WISHLIST);
        remove = (Button) view.findViewById(R.id.REMOVE);
        wishlist.setOnClickListener(this);
        remove.setOnClickListener(this);

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.WISHLIST:
                Toast.makeText(view.getContext(),"Wishlist",Toast.LENGTH_LONG).show();
                break;
            case R.id.REMOVE:
                Toast.makeText(view.getContext(),"Remove",Toast.LENGTH_LONG).show();
                break;
        }
    }
}
}

cartFragment.java

@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.activity_cart, container,false);
    User user = SharedPrefManager.getInstance(getActivity()).getUser();
    userid = user.getUserid();

    recyclerView = (RecyclerView) rootView.findViewById(R.id.cart);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(this.getActivity()));

    total = (TextView) rootView.findViewById(R.id.total);
    checkout = (Button) rootView.findViewById(R.id.checkout);

    cartList = new ArrayList<>();

    loadCart();

    customCartList = new CustomCartList(getActivity(),cartList);
    recyclerView.setAdapter(customCartList);


    return rootView;
}
private void loadCart() {
    String CART_URL = "http://192.168.0.101/cart/cart/cart_view.php?vuserid="+userid;
    Log.e("url",CART_URL+"");
    StringRequest stringRequest = new StringRequest(Request.Method.GET, CART_URL, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            try {
                JSONObject obj = new JSONObject(response);
                JSONArray array = obj.getJSONArray("cart");
                for (int i = 0; i < array.length(); i++){
                    //getting the user from the response
                    JSONObject userJson = array.getJSONObject(i);
                    Cart cart = new Cart();
                    cart.setCartid(userJson.getInt("cartid"));
                    cart.setProductName(userJson.getString("productname"));
                    cart.setPrice(userJson.getString("productprice"));
                    cart.setQty(userJson.getString("quantity"));
                    cartList.add(cart);
                    Log.e("product",userJson+"");
                }
                customCartList.notifyDataSetChanged();
                Log.e("cart",customCartList+"");
                //customCategoryList = new CustomCategoryList(getActivity(),categoryList);
                //recyclerView.setAdapter(customCategoryList);
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

        }
    });
    Volley.newRequestQueue(getActivity()).add(stringRequest);
}

我想显示总计。我从数据库中获取数量和价格。我能够显示每一行的乘法运算，但是我无法显示该列表中的总和。请帮助我。

Answer 1

在CartFragment

中声明一个变量

int totalPrice;

在loadCart()中：

private void loadCart() {
    ...

    cart.setPrice(userJson.getString("productprice"));
    totalPrice += Integer.parseInt(userJson.getString("productprice"));

    ...
}

在onCreateView中：

 total = (TextView) rootView.findViewById(R.id.total);
 checkout = (Button) rootView.findViewById(R.id.checkout);

 cartList = new ArrayList<>();

 loadCart();
 total.setText(totalPrice + ""); // ADD THIS LINE

编辑：在loadCart()中：

cart.setPrice(userJson.getString("productprice"));
cart.setQty(userJson.getString("quantity"));
int price = Integer.parseInt(userJson.getString("productprice"));
int qty = Integer.parseInt(userJson.getString("quantity"));
totalPrice += price*qty;

编辑2

for (int i = 0; i < array.length(); i++){
    ...
}
total.setText(totalPrice + "");
customCartList.notifyDataSetChanged();
...

无法显示自定义Recylerview数据的总和

1 个答案: