无法在列表视图中显示视图的某些JSON数据

时间:2013-09-22 05:30:17

标签: android android-listview

我正在尝试将JSON解析为列表视图

  • log cat
  • 中没有错误
  • 图像被解析但应显示的数据 排名和国家的前面没有显示
  • 为什么会出现错误
  • 如何解决此问题

JSONfunctions.java

public class JSONfunctions {

    public static JSONObject getJSONfromURL(String url) {
        InputStream is = null;
        String result = "";
        JSONObject jArray = null;

        // Download JSON data from URL
        try {
            HttpClient httpclient = new DefaultHttpClient();
            HttpGet httpget = new HttpGet(url);
            HttpResponse response = httpclient.execute(httpget);
            HttpEntity entity = response.getEntity();
            is = entity.getContent();

        } catch (Exception e) {
            Log.e("log_tag", "Error in http connection " + e.toString());
        }

        // Convert response to string
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            result = sb.toString();
        } catch (Exception e) {
            Log.e("log_tag", "Error converting result " + e.toString());
        }

        try {

            jArray = new JSONObject(result);
        } catch (JSONException e) {
            Log.e("log_tag", "Error parsing data " + e.toString());
        }

        return jArray;
    }
}

ListViewAdapter.java

public class ListViewAdapter extends BaseAdapter {

    // Declare Variables
    Context context;
    LayoutInflater inflater;
    ArrayList<HashMap<String, String>> data;
    ImageLoader imageLoader;
    HashMap<String, String> resultp = new HashMap<String, String>();

    public ListViewAdapter(Context context,
            ArrayList<HashMap<String, String>> arraylist) {
        this.context = context;
        data = arraylist;
        imageLoader = new ImageLoader(context);
    }

    @Override
    public int getCount() {
        return data.size();
    }

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    public View getView(final int position, View convertView, ViewGroup parent) {
        // Declare Variables
        TextView rank;
        TextView country;
        ImageView flag;

        inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View itemView = inflater.inflate(R.layout.listview_item, parent, false);
        // Get the position
        resultp = data.get(position);

        // Locate the TextViews in listview_item.xml
        rank = (TextView) itemView.findViewById(R.id.rank);
        country = (TextView) itemView.findViewById(R.id.country);

        // Locate the ImageView in listview_item.xml
        flag = (ImageView) itemView.findViewById(R.id.flag);

        // Capture position and set results to the TextViews
        rank.setText(resultp.get(MainActivity.NAME));
        country.setText(resultp.get(MainActivity.TYPE));
        // Capture position and set results to the ImageView
        // Passes flag images URL into ImageLoader.class
        imageLoader.DisplayImage(resultp.get(MainActivity.FLAG), flag);
        // Capture ListView item click
        itemView.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // Get the position
                resultp = data.get(position);
                Intent intent = new Intent(context, SingleItemView.class);
                // Pass all data rank
                intent.putExtra("name", resultp.get(MainActivity.NAME));
                // Pass all data country
                intent.putExtra("type", resultp.get(MainActivity.TYPE));
                // Pass all data flag
                intent.putExtra("flag", resultp.get(MainActivity.FLAG));
                // Start SingleItemView Class
                context.startActivity(intent);

            }
        });
        return itemView;
    }
}

MainActivity.java

public class MainActivity extends Activity {
    // Declare Variables
    JSONObject jsonobject;
    JSONArray jsonarray;
    ListView listview;
    ListViewAdapter adapter;
    ProgressDialog mProgressDialog;
    ArrayList<HashMap<String, String>> arraylist;
    static String NAME = "rank";
    static String TYPE = "country";
    static String FLAG = "flag";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Get the view from listview_main.xml
        setContentView(R.layout.listview_main);
        // Execute DownloadJSON AsyncTask
        new DownloadJSON().execute();
    }

    // DownloadJSON AsyncTask
    private class DownloadJSON extends AsyncTask<Void, Void, Void> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // Create a progressdialog
            mProgressDialog = new ProgressDialog(MainActivity.this);
            // Set progressdialog title
            mProgressDialog.setTitle("Android JSON Parse Tutorial");
            // Set progressdialog message
            mProgressDialog.setMessage("Loading...");
            mProgressDialog.setIndeterminate(false);
            // Show progressdialog
            mProgressDialog.show();
        }

        @Override
        protected Void doInBackground(Void... params) {
            // Create an array
            arraylist = new ArrayList<HashMap<String, String>>();
            // Retrieve JSON Objects from the given URL address
            jsonobject = JSONfunctions
                    .getJSONfromURL("http://54.218.73.244:7002/");

            try {
                // Locate the array name in JSON
                jsonarray = jsonobject.getJSONArray("restaurants");

                for (int i = 0; i < jsonarray.length(); i++) {
                    HashMap<String, String> map = new HashMap<String, String>();
                    jsonobject = jsonarray.getJSONObject(i);
                    // Retrive JSON Objects
                    map.put("name", jsonobject.getString("restaurantNAME"));
                    map.put("type", jsonobject.getString("restaurantTYPE"));
                    map.put("flag", jsonobject.getString("restaurantIMAGE"));
                    // Set the JSON Objects into the array
                    arraylist.add(map);
                }
            } catch (JSONException e) {
                Log.e("Error", e.getMessage());
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void args) {
            // Locate the listview in listview_main.xml
            listview = (ListView) findViewById(R.id.listview);
            // Pass the results into ListViewAdapter.java
            adapter = new ListViewAdapter(MainActivity.this, arraylist);
            // Set the adapter to the ListView
            listview.setAdapter(adapter);
            // Close the progressdialog
            mProgressDialog.dismiss();
        }
    }
}

输出

图像正在解析但是应该在排名和国家/地区之前显示的数据未显示

任何想法

希望我很清楚

2 个答案:

答案 0 :(得分:0)

  

图像被解析但应显示的数据   排名和国家的前面没有显示

因为您使用不同的密钥在HashMap中存储值并尝试在Adapter中使用不同的密钥获取值,因此将其更改为内部doInBackground方法,以便使用密钥存储值:

map.put(MainActivity.NAME, jsonobject.getString("restaurantNAME"));
map.put(MainActivity.TYPE, jsonobject.getString("restaurantTYPE"));
map.put(MainActivity.FLAG, jsonobject.getString("restaurantIMAGE"));

答案 1 :(得分:0)

尝试以下代码:

@Override
public Object getItem(int position) {
    return position;
}

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

并且您的地图密钥也不同:请参阅restaurantNAME ...