Question

I’m having a problem refresh the data in list view.
I get the data in the list from a server, and when I want to refresh the data I need to go to the server and receive the new data.
the notifyDataSetChanged() not helping and also the ListView.invalidateViews not helping.
when I rotate the device the list updated.
how can I load the list view in the same way the screen rotation do it?

This is the code on create that fill the list view.

thanks in advance.

query = new ParseQuery(PET_CLASS_NAME);
petListView.addHeaderView((View)getLayoutInflater().inflate(R.layout.header_row, null));        
petDetailIntent = new Intent(getApplicationContext(), PetDetailActivity.class);
    selectCityIntent = new Intent(this, CitiesActivity.class);
    loadingIntent = new Intent(getApplicationContext(), LoadingActivity.class);
    startActivityForResult(loadingIntent, LOADING_INTENT_CODE);                     

    /*the user see list of pets that are still missing*/
    query.whereEqualTo(PET_FOUNDED, false);
    selectedCity = settings.getString("cityQuery", "");
    if(selectedCity != ""){
        query.whereEqualTo(PET_CITY, selectedCity);
    }
    query.findInBackground(new FindCallback() {

        @Override
        public void done(List<ParseObject> list, ParseException e) {
            if (e == null) { //objects retrieved well                   
                petList.addAll(list);

                //MyAdapter
                adapter = new MyAdapter(
                        getApplicationContext(), 
                        android.R.layout.simple_list_item_1, 
                        R.id.tv_pet_name,
                        petList);

                setListAdapter(adapter);
            }
            else{
                toaster(getResources().getString(R.string.error_message_load_pets));
                finish();
            }           
            finishActivity(LOADING_INTENT_CODE);                        
        }       
    });

Answer 1

Use a AsyncTask for loadData from Server. It will load it faster.

Try this out:

private class YourTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... s) {

            //Here you have to make the loading / parsing tasks
            //Don't call any UI actions here. For example a Toast.show() this will couse Exceptions
            // UI stuff you have to make in onPostExecute method

        }

        @Override
        protected void onPreExecute() {
            // This method will called during doInBackground is in process
            // Here you can for example show a ProgressDialog
        }

        @Override
        protected void onPostExecute(Long result) {
            // onPostExecute is called when doInBackground finished
            **// Here you can for example fill your Listview with the content loaded in doInBackground method**


        }

}

And than you just have to call this AsyncTask always if you loading content from your server:

new YourTask().execute("");

Try it out!.. Hope this helps..