Content view not yet created in refreshing a list fragment

Question

SOLUTION: It was a case of having 2 different instances of WinnersFragment which caused the lv = getListView() to be null on the refresh.

My fragment list view works fine on load. However when I call public static void InitTask(String searchState). I get Content view not yet created at lv = getListView().

My goal is to just refresh the listview with new json.

I have tried calling getlistView in pre execute and I have tried using a new inittask.
I believe it has something to do with creating a new instance of the WinnersFragment but I am not sure.

I found this "Content view not yet Created" on Android Fragments but while I understand it hitting the main thread I do not understand how to implement the solution to see if that is my issue.

 public class WinnersFragment extends ListFragment {
private static String URL = "http://www.xxx.com/RichardsTesting/winners.json";

Context context;
Winners_List_Adapter adapter;
static View v;
ListView lv;
ArrayList<String> alFName;
private ProgressDialog pd;
private static final String TAG_ID = "id";
private static final String TAG_FNAME = "fname";
private static final String TAG_STATE = "state";
private static final String TAG_CODE = "code";
private static final String TAG_AMOUNT = "amount";

ArrayList<HashMap<String, String>> winnersList;

JSONArray winners = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    v = inflater.inflate(R.layout.winners_list, container, false);
    context = getActivity().getApplicationContext();
    new InitTask().execute();

    return v;
}

@Override
public void onDestroy() {
    lv.setAdapter(null);
    super.onDestroy();
}

protected class InitTask extends AsyncTask<Context, Integer, String> {
    @Override
    protected void onPreExecute() {
        pd = new ProgressDialog(v.getContext());
        pd.setTitle("Updating...");
        pd.setMessage("Please wait.");
        pd.setCancelable(false);
        pd.setIndeterminate(true);
        pd.show();
    }

    @Override
    protected String doInBackground(Context... params) {
        // Hashmap for ListView
        winnersList = new ArrayList<HashMap<String, String>>();

        // Creating JSON Parser instance
        JSONParser jParser = new JSONParser();

        // getting JSON string from URL
        String json = jParser.getJSONFromUrl(URL);
        try {
            JSONArray json1 = new JSONArray(json);

            // looping through All Contacts
            for (int i = 0; i < json.length(); i++) {
                JSONObject c = json1.getJSONObject(i);

                // Storing each json item in variable
                String id = c.getString(TAG_ID);
                String fName = c.getString(TAG_FNAME);
                String state = c.getString(TAG_STATE);
                String code = c.getString(TAG_CODE);
                String amount = c.getString(TAG_AMOUNT);

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

                // adding each child node to HashMap key => value
                map.put(TAG_ID, id);
                map.put(TAG_FNAME, fName);
                map.put(TAG_STATE, state);
                map.put(TAG_CODE, code);
                map.put(TAG_AMOUNT, amount);

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

        return "COMPLETE!";
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(String result) {
        super.onPostExecute(result);
        // selecting single ListView item
        lv = getListView();
        if (pd != null) {
            pd.dismiss();
        }
        setListWinners();
    }
}

public void setListWinners() {
    adapter = new Winners_List_Adapter(this.getActivity(), winnersList);
    lv.setAdapter(adapter);
}

public static void InitTask(String searchState) {
    if (searchState !=null) {
    URL = URL+"?state="+searchState;
    WinnersFragment search = new WinnersFragment();
    search.new InitTask().execute();
    }
}
}

LOG

12-04 13:01:48.156: E/AndroidRuntime(1367): FATAL EXCEPTION: main
12-04 13:01:48.156: E/AndroidRuntime(1367): java.lang.IllegalStateException: Content view not yet created
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.support.v4.app.ListFragment.ensureList(ListFragment.java:328)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.support.v4.app.ListFragment.getListView(ListFragment.java:222)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at com.xxx.xxx.WinnersFragment$InitTask.onPostExecute(WinnersFragment.java:123)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at com.xxx.xxx.WinnersFragment$InitTask.onPostExecute(WinnersFragment.java:1)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.os.AsyncTask.finish(AsyncTask.java:631)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.os.Looper.loop(Looper.java:137)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at android.app.ActivityThread.main(ActivityThread.java:4898)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at java.lang.reflect.Method.invokeNative(Native Method)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at java.lang.reflect.Method.invoke(Method.java:511)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775)
12-04 13:01:48.156: E/AndroidRuntime(1367):     at dalvik.system.NativeStart.main(Native Method)

xml

  <ListView
    android:id="@id/android:list"
    android:layout_width="match_parent"
    android:layout_height="0dip"
    android:layout_weight="1"
    android:drawSelectorOnTop="false" />

Calling Fragment code

public class TabsFragmentActivity extends FragmentActivity implements
    FragmentTabHost.OnTabChangeListener, OnClickListener {
      blablabla
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
    case R.id.btnDismiss:
        getSupportFragmentManager().popBackStackImmediate();
        break;
    case R.id.ibSearch:
        LayoutInflater inflater = LayoutInflater.from(this);
        final View textenter = inflater.inflate(R.layout.winners_list, null);
        final EditText userinput = (EditText) textenter
                .findViewById(R.id.etSearchState);
        String searchState = userinput.toString();
        WinnersFragment.InitTask(searchState);
        break;  
    }
}

Answer 1

Try to execute your background task inside onActivityCreated() method.

Fragment Lifecycle

Answer 2

onCreateView  

Returns a view that is displayed for this fragment as you are trying to access listview before returning this view you are getting that error.

Try doing what @Makario said or else get the list view reference in onCreateView by:

 v = inflater.inflate(R.layout.winners_list, container, false);
 context = getActivity().getApplicationContext();
 listView=v.findViewById(R.id.list);
 new InitTask().execute();

And use this listview object in your task.

Answer 3

As the error message indicates, your ListView's view hasn't yet been created. (You're calling it in onCreateView, and even though the method runs asynchronously, you're trying to access the ListView before it has been completely setup.)

Move the InitTask().execute() to either onViewCreated or onActivityCreated instead.