如何使用JSON对象传递JSON数组

本文介绍了如何使用JSON对象传递JSON数组的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

GridView控件包含类别，当我做水龙头上的任何GridView的项目（即 - 任何类别）。我想证明这些物品属于只在ViewPager特定类别

例如，我有两个类别第一 - 电子和第二 - 家电，仍然每当我做水龙头在家电类别 - 它显示所有的项目（从电子1到电器2 ），而它显示唯一项目那些下的家电类别

问题

仍然显示在ViewPager的所有项目，无论哪一类已被用户窃听.... 如何可以我证明这些物品属于窃听类别只？

公共类MainActivity延伸活动{    ArrayList的＆LT;项目＆GT; itemsArrayList;    ...    @覆盖    保护无效的onCreate（捆绑savedInstanceState）{        super.onCreate（savedInstanceState）;        的setContentView（R.layout.activity_main）;        itemsArrayList =新的ArrayList＆LT;项目＆GT;（）;        ...        gridView.setOnItemClickListener（新OnItemClickListener（）{            @覆盖            公共无效onItemClick（适配器视图＆LT;＆GT;为arg0，ARG1查看，INT位置，                    长ID）{                。字符串categoryName = menusArrayList.get（位置）.getName（）的toString（）;                Log.d（类别名称，类别名称）;                菜单= menusArrayList.get（位置）;                itemsArrayList = menus.getItemsArrayList（）;                适配器=新ViewPagerAdapter（MenusActivity.this，R.layout.adapter_viewpager，itemsArrayList）;                viewPager.setAdapter（适配器）;            }        }）;    }    类JSONAsyncTask扩展的AsyncTask＆LT;弦乐，太虚，布尔＆GT; {        ProgressDialog对话框;        @覆盖        在preExecute保护无效（）{            super.on preExecute（）;        }        @覆盖        保护布尔doInBackground（字符串的URL ...）{            尝试{                .....                    JSONArray jsonArray = jsonObject.getJSONArray（类）;                    的for（int i = 0; I＆LT; jsonArray.length（）;我++）{                        JSONObject的jObject = jsonArray.getJSONObject（I）                        菜单=新菜单（）;                        menus.setName（jObject.getString（名字））;                        menus.setImage（jObject.getString（图像））;                        JSONArray imagesArray = jObject.getJSONArray（项目）;                        对于（INT J = 0; J＆LT; imagesArray.length（）; J ++）                        {                            JSONObject的imagesObject = imagesArray.getJSONObject（J）;                            项目=新项目（）;                            items.setTitle（imagesObject.getString（标题））;                            items.setImage（imagesObject.getString（图像））;                            itemsArrayList.add（项目）;                        }                        menus.setItemsArrayList（itemsArrayList）;                        menusArrayList.add（菜单）;                    }                    返回true;                }                ...            返回false;        }        保护无效onPostExecute（布尔结果）{            dialog.cancel（）;            ...        }    }}

解决方案

您itemArrayList是全球性的，并在解析你每次你读一个类别时将项目添加到该列表。出于这个原因，你itemListArray包含的所有项目。既然是参考列表时，您将项目添加到列表中，你也增加项目previous类，因为它们引用相同的列表。试着改变你的内循环是这样的。

的ArrayList＆LT;项目＆GT; itemsArrayList =新的ArrayList＆LT;项目＆GT;（）;对于（INT J = 0; J＆LT; imagesArray.length（）; J ++）                        {                        JSONObject的imagesObject = imagesArray.getJSONObject（J）;                    项目=新项目（）;                    items.setTitle（imagesObject.getString（标题））;                    items.setImage（imagesObject.getString（图像））;                    itemsArrayList.add（项目）;                }

GridView contains Categories, and when I do tap on any of the GridView item (i.e - any Category) i would like to show items those belongs to that particular Category only in ViewPager.

For example, I have two categories first - Electronics and second - Appliances, still whenever i do tap on Appliances category - it showing all the items (from Electronics 1 to Appliances 2) whereas it has to show only items those are under Appliances category

ISSUE

Still showing all the items in a ViewPager, no matter which category has been tapped by user.... How may i show those Items that belongs to tapped Category only ?

public class MainActivity extends Activity { ArrayList<Items> itemsArrayList; ... @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); itemsArrayList = new ArrayList<Items>(); ... gridView.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int position, long id) { String categoryName = menusArrayList.get(position).getName().toString(); Log.d("categoryName:", categoryName); menus = menusArrayList.get(position); itemsArrayList = menus.getItemsArrayList(); adapter = new ViewPagerAdapter(MenusActivity.this, R.layout.adapter_viewpager, itemsArrayList); viewPager.setAdapter(adapter); } }); } class JSONAsyncTask extends AsyncTask<String, Void, Boolean> { ProgressDialog dialog; @Override protected void onPreExecute() { super.onPreExecute(); } @Override protected Boolean doInBackground(String... urls) { try { ..... JSONArray jsonArray = jsonObject.getJSONArray("category"); for (int i = 0; i < jsonArray.length(); i++) { JSONObject jObject = jsonArray.getJSONObject(i); menus = new Menus(); menus.setName(jObject.getString("name")); menus.setImage(jObject.getString("image")); JSONArray imagesArray = jObject.getJSONArray("items"); for(int j=0; j<imagesArray.length(); j++) { JSONObject imagesObject = imagesArray.getJSONObject(j); items = new Items(); items.setTitle(imagesObject.getString("title")); items.setImage(imagesObject.getString("image")); itemsArrayList.add(items); } menus.setItemsArrayList(itemsArrayList); menusArrayList.add(menus); } return true; } ... return false; } protected void onPostExecute(Boolean result) { dialog.cancel(); ... } } }

解决方案

Your itemArrayList is global and on parsing you're adding items to that list each time you read a category. For that reason your itemListArray include all items. Since it is reference to a list when you add an item to list, you're also adding item to previous categories since they reference to same list. Try changing your inner loop like this.

ArrayList<Items> itemsArrayList = new ArrayList<Items>(); for(int j=0; j<imagesArray.length(); j++) { JSONObject imagesObject = imagesArray.getJSONObject(j); items = new Items(); items.setTitle(imagesObject.getString("title")); items.setImage(imagesObject.getString("image")); itemsArrayList.add(items); }