如何在列表视图中显示来自arraylist的所有解析数据？

Posted 2023-02-26

【中文标题】如何在列表视图中显示来自arraylist的所有解析数据？

【英文标题】：How to show all parse data from arraylist in list view?

【发布时间】：2017-11-13 16:44:54

【问题描述】：

这是我的 JSON 数据

 "products": 
"617491704": 
  "user_id": "908",
  "product_id": 9683,
  "product": "Kishmish Raisins Sonaka 250 gm"
, "1405688942": 
  "user_id": "908",
  "product_id": 9683,
  "product": "Kishmish Raisins Sonaka 250 gm", "617491704": 
  "product_id": 9683,
  "product": "Kishmish Raisins Sonaka 250 gm"

这是我解析 JSON 数据的代码

public static ArrayList<CartData> ParseData(String response) throws JSONException 

    ArrayList<CartData> aluser = null;

    JSONObject jsonRoot = new JSONObject(response);

    JSONObject jsonObject = jsonRoot.getJSONObject("products");

    CartData details1 = new CartData();
        aluser = new ArrayList<>();
        Iterator<String> keys = jsonObject.keys();
        while (keys.hasNext()) 


            String key = keys.next();
            JSONObject inside = jsonObject.getJSONObject(key);
            details1.setId(inside.getString("product_id"));
            details1.setProductname(inside.getString("product"));

            aluser.add(details1);


    
        return aluser;
    

问题是，它只显示 ListView 中 arraylist 的最后一个值。请建议，我的代码中的问题在哪里。 这是我的 ListView 适配器。

private class AdapterCommentListcart extends BaseAdapter 
    private Context context;

    private List<CartData> alComments;

    private LayoutInflater inflater;


    public AdapterCommentListcart(Context context, List<CartData> alComments) 
        this.context = context;

        this.alComments = alComments;

        inflater = LayoutInflater.from(this.context);
    

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 
        AdapterCommentListcart.ViewHolder holder = null;

        if (mapViewHolder.get(position) == null) 
            convertView = inflater.inflate(R.layout.products, null);

            holder = initHolder(convertView, position);

            attachEvents(holder, position);

            convertView.setTag(holder);

            mapViewHolder.put(position, convertView);
         else 
            holder = (AdapterCommentListcart.ViewHolder) mapViewHolder.get(position).getTag();
        

        updateHolder(holder, position);

        return mapViewHolder.get(position);
    

    @Override
    public int getCount()

    
        return alComments.size();
    

    @Override
    public CartData getItem(int position) 
        return alComments.get(position);
    

    @Override
    public long getItemId(int position) 
        return position;
    

    private class ViewHolder 

        private TextView tvName;
        private TextView tvprice;
        

    private AdapterCommentListcart.ViewHolder initHolder(View convertView, int pos) 
        AdapterCommentListcart.ViewHolder holder = new AdapterCommentListcart.ViewHolder();

        holder.tvName = (TextView) convertView.findViewById(R.id.id);
        holder.tvprice = (TextView) convertView.findViewById(R.id.name);

        return holder;
    


    private void updateHolder(final AdapterCommentListcart.ViewHolder holder, final int pos) 

        holder.tvName.setText(alProduct.get(pos).getId());
        holder.tvprice.setText(alProduct.get(pos).getProductname());


    

    private void attachEvents(AdapterCommentListcart.ViewHolder holder, final int position) 

    

【问题讨论】：

您是否尝试使用 JSONArray 而不是 JSONObject？

我建议你使用 Gson 进行 JSON 解析

【参考方案1】：

将 CartData details1 放入 while 循环中。你只创建了一次对象，你应该在循环中每次都创建一个对象。

public static ArrayList<CartData> ParseData(String response) throws JSONException 

    ArrayList<CartData> aluser = new ArrayList<>();

    JSONObject jsonRoot = new JSONObject(response);

    if (jsonRoot == null) 
        return aluser;
    

    JSONObject jsonObject = jsonRoot.optJSONObject("products");

    if (jsonObject == null) 
        return aluser;
    

    Iterator<String> keys = jsonObject.keys();

    while (keys.hasNext()) 
        String key = keys.next();

        if (TextUtils.isEmpty(key)) 
            continue;
        

        JSONObject inside = jsonObject.optJSONObject(key);

        if (inside == null) 
            continue;
        

        String productId = inside.optString("product_id");
        String product = inside.optString("product");

        if(TextUtils.isEmpty(product) || TextUtils.isEmpty(productId)) 
            continue;
        

        CartData details1 = new CartData();
        details1.setId(productId);
        details1.setProductname(product);

        aluser.add(details1);


    
    return aluser;

【参考方案2】：

只有问题是这条线

 CartData details1 = new CartData();

它只创建一次对象，并且您每次都在 while 循环中添加同一个对象，因此不是只创建一次对象，而是每次在 while 循环中使用新数据创建它，而不是像下面这样添加。

public static ArrayList ParseData(String response) throws JSONException

ArrayList<CartData> aluser = null;

JSONObject jsonRoot = new JSONObject(response);

JSONObject jsonObject = jsonRoot.getJSONObject("products");


    aluser = new ArrayList<>();
    Iterator<String> keys = jsonObject.keys();
    while (keys.hasNext()) 

        CartData details1 = new CartData();
        String key = keys.next();
        JSONObject inside = jsonObject.getJSONObject(key);
        details1.setId(inside.getString("product_id"));
        details1.setProductname(inside.getString("product"));

        aluser.add(details1);



    return aluser;

【讨论】：

与其他答案有什么不同..？