android - Order App - Android 将值数组发布到数据库

Question

我正在为我正在处理的项目的一部分创建一个订单应用程序。基本上，在一项活动中，用户可以查看从数据库中提取的所有项目的列表作为 ListView。他们还有一个 EditText 字段，他们可以在其中输入他们想要在每个项目下方订购的数量。

我想在屏幕底部有一个提交按钮，然后将发布所有订购商品的详细信息（即它们的商品 ID）和订购数量，但我不确定如何执行此操作。

这是我当前的代码：

public class OrderItems extends AppCompatActivity {

    String menuID;
    private TextView menuTitle;

    ListView listView;
    List<OrderItemList> listOrderItems;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_order_items);

        menuTitle = findViewById(R.id.tvOrderMenuTitle);

        Intent intent = getIntent();
        String title = intent.getStringExtra("title");
        menuID = intent.getStringExtra("id");

        menuTitle.setText(title);

        listView = findViewById(R.id.list_order_items);
        listOrderItems = new ArrayList<>();

        displayItems();  

    }

    private void displayItems(){
        String url = "hidden";
        StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
                    JSONObject obj = new JSONObject(response);
                    JSONArray array = obj.getJSONArray("menuitems");

                    for (int i = 0; i < array.length(); i++) {
                        final JSONObject menuObj = array.getJSONObject(i);
                        OrderItemList o = new OrderItemList(menuObj.getString("menu_item_name"),
                                menuObj.getString("item_type"), menuObj.getInt("menu_item_price"), menuObj.getInt("menu_item_qty"));
                        listOrderItems.add(o);
                    }
                    OrderItemAdapter adapter = new OrderItemAdapter(listOrderItems, getApplicationContext());
                    listView.setAdapter(adapter);

                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(OrderItems.this, "Oops! " +error.toString(), Toast.LENGTH_LONG).show();
            }
        }){
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {

                Map<String, String> params = new HashMap<>();
                params.put("menuid", menuID);
                return params;
            }

        };

        MySingleton.getInstance(this).addToRequestQueue(stringRequest);
    }
}

尽管我无法在 EditText 框中输入要订购的项目数量，但显示项目工作正常，一旦我输入它然后转到下一个框，之前的值就会消失。

模型类如下所示：

public class OrderItemList {

    String Name, Type;
    int Price, Qty;

    public OrderItemList(String name, String type, int price, int qty) {
        Name = name;
        Type = type;
        Price = price;
        Qty = qty;
    }

    public String getName() {
        return Name;
    }

    public int getQty() {
        return Qty;
    }

    public String getType() {
        return Type;
    }

    public int getPrice() {
        return Price;
    }

}

和适配器：

public class OrderItemAdapter extends ArrayAdapter <OrderItemList>{

    private List<OrderItemList> orderItemList1;
    private Context context;

    public OrderItemAdapter(List<OrderItemList> M, Context C){
        super(C, R.layout.listorder, M);
        this.orderItemList1 = M;
        this.context = C;

    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LayoutInflater layoutInflater = LayoutInflater.from(context);
        View view = layoutInflater.inflate(R.layout.listorder,null,true);

        TextView menuItemName = view.findViewById(R.id.tvItemName);
        TextView menuItemPrice = view.findViewById(R.id.tvItemPrice);
        TextView menuItemType = view.findViewById(R.id.tvItemType);
        TextView menuItemQty = view.findViewById(R.id.tvItemQty);


        OrderItemList orderItemList = orderItemList1.get(position);

        menuItemName.setText(orderItemList.getName());
        menuItemQty.setText("Available quantity: " +orderItemList.getQty());
        menuItemPrice.setText("£" +orderItemList.getPrice());
        if(position>0){
            OrderItemList prevOrderItemList = orderItemList1.get(position-1);
            if(!orderItemList.getType().equals(prevOrderItemList.getType())){
                menuItemType.setText(orderItemList.getType());
            }
        } else {
            menuItemType.setText(orderItemList.getType());
        }





        return view;

    }



}

任何帮助/建议将不胜感激！

标签： androidarraysjson