setListAdapter不显示内容

Question

我试图通过使用#include <iostream> #include <vector> #include <chrono> void f() { std::vector<int*> vpi {}; int i {}; try{ for(;;){ int* pi = new int[10000]; vpi.push_back(pi); // ++i; // std::cout << "Allocated " << i*80 << " MB so far\n"; } } catch(std::bad_alloc){ std::cerr << "Memory exhausted\n"; } } int main() { auto t0 = std::chrono::high_resolution_clock::now(); f(); auto t1 = std::chrono::high_resolution_clock::now(); std::cout << std::chrono::duration_cast<std::chrono::milliseconds>(t0-t1).count() << " ms\n"; } 解析JSON来实现自定义适配器。一切看起来都不错，但手机屏幕上没有显示任何内容。 除了线。请帮我解决一下这个。 setListAdapter正在解析并存储在JSON ArrayList中。

jsonlist

activity_main.xml中

public class MainActivity extends ListActivity {
    final String TAG = "MAINActivity.java";
    ListView listView;
    private static final String STATION = "stationName";
    private static final String DOCKS = "availableDocks";

    ArrayList<HashMap<String, String>> jsonlist = new ArrayList<HashMap<String, String>>();
    private Context context;
    ListView lv ;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        new AsynctaskParseJson(MainActivity.this).execute();
    //  listView=(ListView)findViewById();
    }

    public class AsynctaskParseJson extends AsyncTask<String, String, String> {
        private ListActivity activity;
        private ProgressDialog dialog;
        public AsynctaskParseJson(ListActivity mainActivity) {
            // TODO Auto-generated constructor stub

            this.activity = mainActivity;
            context = activity;
            dialog=new ProgressDialog(context);
        }
        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
            this.dialog.setMessage("Progress start");
            this.dialog.show();
            super.onPreExecute();
        }
        private Context context;
        @Override
        protected void onPostExecute(String result) {
            // TODO Auto-generated method stub

            super.onPostExecute(result);
            if (dialog.isShowing()) {
                dialog.dismiss();
            }
            /*ArrayAdapter<HashMap<String, String>> adapter = new ArrayAdapter<HashMap<String, String>>(
                    context, R.layout.list_item, jsonlist);*/
            Log.d("JSON LIST", "Headline: " + jsonlist.toString());
            Log.d("Elements", "Headline: " + context.toString());
            Log.d("Elements", "Station: " + STATION);

            ListAdapter adapter = new SimpleAdapter(context, jsonlist, R.layout.list_item, new String[] { STATION, DOCKS}, new int[] { R.id.editText1, R.id.editText2 });

            setListAdapter(adapter);
            lv = getListView();
            getListView().setTextFilterEnabled(true);
        }

        String strURL = "http://www.citibikenyc.com/stations/json";
        JSONArray jArray = null;

        @Override
        protected String doInBackground(String... params) {
            // TODO Auto-generated method stub
            JSONParser jParser = new JSONParser();
            JSONObject jObject = jParser.getJSONFromURL(strURL);
            //Log.e("NITIN", "Headline: " + jObject);
            try {
                jArray = jObject.getJSONArray("stationBeanList");
                for (int i = 0; i < jArray.length(); i++) {
                    JSONObject c = jArray.getJSONObject(i);
                    String headLine = c.getString(STATION);
                    String agency = c.getString(DOCKS);
                    HashMap<String, String> map = new HashMap<String, String>();
                    map.put(headLine, STATION);
                    map.put(agency, DOCKS);
                    jsonlist.add(map);

                }
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return null;
        }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >


    <ListView
        android:id="@android:id/list"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

JSON解析器类：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/editText2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>