0

我正在使用带有操作栏夏洛克片段的导航抽屉。我有一个主要活动并从那里调用四个片段。在其中一个片段中，需要显示产品列表。我能够成功获取和解析 json 数据。但是，无法在我的布局中显示列表。在 logcat 中，直到显示“线程中”。之后，应用程序崩溃。

        class LoadEnq extends AsyncTask<String, String, String> {

        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(getActivity());
            pDialog.setMessage("Listing Enquiries ...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }

        /**
         * getting Albums JSON
         * */
        protected String doInBackground(String... args) {
            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("TOKEN", "INBOX-S!U@B#O$"));
            params.add(new BasicNameValuePair("ACTION", "inbox"));
            params.add(new BasicNameValuePair("MODID", "IMOB"));
            params.add(new BasicNameValuePair("GLID", "423104"));
            params.add(new BasicNameValuePair("FOLDER", "1"));
            params.add(new BasicNameValuePair("FROM", "0"));
            params.add(new BasicNameValuePair("TO", "500"));            


            // getting JSON string from URL
            String json = jsonParser.makeHttpRequest(URL_ENQ, "POST",
                    params);

            // Check your log cat for JSON reponse
            Log.d("Enq JSON: ", "> " + json);

            try {       
                System.out.println("in try");
                enq = new JSONArray(json);

                if (enq != null) {
                    // looping through All albums
                    for (int i = 0; i < enq.length(); i++) {
                        JSONObject c = enq.getJSONObject(i);

                        // Storing each json item values in variable
                        String qid = c.getString(TAG_QID);
                        String qtype = c.getString(TAG_QTYPE);
                        String name = c.getString(TAG_SNAME);
                        String email = c.getString(TAG_SEMAIL);
                        String subject = c.getString(TAG_SUBJECT);
                        System.out.println("QID" + qid);
                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();

                        // adding each child node to HashMap key => value
                        map.put(TAG_QID, qid);
                        map.put(TAG_QTYPE, qtype);
                        map.put(TAG_SNAME, name);
                        map.put(TAG_SEMAIL, email);
                        map.put(TAG_SUBJECT, subject);
                        // adding HashList to ArrayList
                        enqList.add(map);
                    }
                }else{
                    Log.d("Enquries: ", "null");
                }

            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }

        /**
         * After completing background task Dismiss the progress dialog
         * **/
        protected void onPostExecute(String file_url) {
            System.out.println("post");
            // dismiss the dialog after getting all albums
            pDialog.dismiss();
            System.out.println("dismiss");   
            // updating UI from Background Thread
            //getActivity().runOnUiThread(new Runnable() {
                //public void run() {
                    System.out.println("in thread");
                    /**
                     * Updating parsed JSON data into ListView
                     * */

                    ListAdapter adapter = new SimpleAdapter(
                            getActivity(), enqList,
                            R.layout.list_item_albums, new String[] { TAG_QID,TAG_QTYPE,
                                    TAG_SNAME, TAG_SEMAIL,TAG_SUBJECT }, new int[] {
                                    R.id.query_id,R.id.qtype ,R.id.name,R.id.email, R.id.subject });

                    //adapter.notifyDataSetChanged();
                    // updating listview
                    setListAdapter(adapter);



                //}
            //});

        }
        }

}

堆栈跟踪：

07-09 12:21:02.374: E/AndroidRuntime(482): FATAL EXCEPTION: main
07-09 12:21:02.374: E/AndroidRuntime(482): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(16908298, class android.widget.ListView) with Adapter(class android.widget.SimpleAdapter)]
07-09 12:21:02.374: E/AndroidRuntime(482):  at android.widget.ListView.layoutChildren(ListView.java:1492)
07-09 12:21:02.374: E/AndroidRuntime(482):  at android.widget.AbsListView.onLayout(AbsListView.java:1147)
07-09 12:21:02.374: E/AndroidRuntime(482):  at android.view.View.layout(View.java:7035)
07-09 12:21:02.374: E/AndroidRuntime(482):  at android.widget.RelativeLayout.onLayout(RelativeLayout.java:909)
4

1 回答 1

1

你应该像这样使用thms

public class YourFragment extends SherlockListFragment{

    private ListAdapter adapter;


    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        new YourTask().execute();
    }   


    public class YourTask extends AsyncTask<Object, Void, List<Map<String,String>>> {

    @Override
    protected List<Map<String,String>> doInBackground(Object... objects) {
        List<Map<String,String>> list = new LinkedList<Map<String, String>>();

        for (int i = 0; i < enq.length(); i++) {

            // ... your json
            list.add(map);

        }
        return list;
    }


    protected void onPostExecute(List<Map<String,String>> result) {
        if (pDialog.isShowing())
            pDialog.dismiss();

        if (YourFragment.this.isAdded()){

            adapter = new SimpleAdapter(
                    getActivity(), result, 
                    R.layout.list_item_albums, new String[] { TAG_QID,TAG_QTYPE,
                    TAG_SNAME, TAG_SEMAIL,TAG_SUBJECT }, new int[] {
                    R.id.query_id,R.id.qtype ,R.id.name,R.id.email, R.id.subject });
            setListAdapter(adapter);
        }

    }
};

}

于 2013-07-09T07:15:56.380 回答