从listAdapter提取项目

Question

我从数据库的JSON文件填充ArrayList并将它们加载到ListAdapter中。 我的代码：

private JSONArray mList = null;
private ArrayList<HashMap<String, String>> mItemList;
...
public void updateJSONdata() {
mItemList = new ArrayList<HashMap<String, String>>();

    JSONParser jParser = new JSONParser();
    JSONObject json = jParser.getJSONFromUrl(READ_COMMENTS_URL);

    try {
        mList = json.getJSONArray(TAG_ITEMS_REPORT);
        for (int i = 0; i < mList.length(); i++) {
            JSONObject c = mList.getJSONObject(i);

            // gets the content of each tag
            String iName = c.getString(TAG_ITEM_NAME);
            ...

            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            map.put(TAG_ITEM_NAME, iName);
           ...

            // adding HashList to ArrayList
            mItemList.add(map);
        }
} catch (JSONException e) {
        e.printStackTrace();
    }
}

在这里，我更新了我的ListAdapter并设置了onItemCLick

 private void updateList() {
    final ListAdapter adapter = new SimpleAdapter(this, mItemList,
            R.layout.single_item_view,
            new String[]{TAG_ITEM_NAME, TAG_ITEM_INFO,
                    TAG_ITEM_QUANTITY, TAG_ITEM_COMMENT, TAG_ITEM_LOCATION},
            new int[]{R.id.singleItemView_itemName, R.id.singleItemView_ItemInfo,
                    R.id.login_username});

    setListAdapter(adapter);
    final ListView lv = getListView();
    lv.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View viewClicked,
                                int position, long id) {
            String lst = mItemList.get(position).toString();
            Toast.makeText(ReportViewer.this, "Position " + parent.getItemAtPosition(position), Toast.LENGTH_LONG).show();
            Log.d(" ReportView onItemClick",  
         });
    }

现在，我很确定String lst不是提取数据的最优雅，最正确的方法。 它确实为我单击的每个位置提供了正确的字符串，但是所有值显然都包含在一个字符串中。 如何一次提取一个值，例如TAG_ITEM_IFNO？ 谢谢。

Answer 1

您可以这样做：

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    // 1st Approach
    HashMap<String, String> map = (HashMap<String, String>) l.getItemAtPosition(position);
    Set<Entry<String, String>> entrySet = map.entrySet();
    for(Entry<String, String> entry: entrySet) {
        String key=entry.getKey();
        String value=entry.getValue();
        if(key=="your_key_that_you_have_mapped_to_some_textview_in_your_layout") {
            // do what you want
        }
    }

    // 2nd Approach
    TextView tv=(TextView) v.findViewById(R.id.login_username);
    String myvalue=tv.getText().toString();
}

代替：

final ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> parent, View viewClicked,
                            int position, long id) {
        String lst = mItemList.get(position).toString();

Answer 2

这对我来说是个窍门

mItemList.get(position).get(value)

在代码中

 @Override
    public void onItemClick(AdapterView<?> parent, View viewClicked,
                            int position, long 
         Toast.makeText(ReportViewer.this, "Position " + mItemList.get(position).get(TAG_ITEM_COMMENT), Toast.LENGTH_LONG).show();;
        Log.d(" ReportView onItemClick",  mItemList.get(position).get(TAG_ITEM_COMMENT))
     });
}