Listview in the Asynctask

Question

My code does not load the data to list view when ta inside the AsyncTask, but if it is placed in the onCreateView works perfectly.

public class Tab_os_Fechadas extends Fragment {

    private String url ="http://redeml.no-ip.info/controleos/mobile/list_os_fechadas.php";
    private String parametros ="";
    private  ListView listOSFechadas;
    private int i;

    private LayoutInflater inflater;


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


       View x =  inflater.inflate(R.layout.tab_os_fechada,null);

        new SolicitarDados().execute(url);
        return x;

    }

    private  class SolicitarDados extends AsyncTask<String, Void,String > {


        View view;

        @Override
        protected String doInBackground(String... urls) {
            return ConexaoDB.postDados(urls[0], parametros);
        }

        @Override
        protected void onPostExecute(String result) {

            try {
                JSONArray jsonarray = new JSONArray(result);
                for (int i = 0; i < jsonarray.length(); i++) {
                    JSONObject jsonobject = jsonarray.getJSONObject(i);

                }


                ArrayList<ItemOSFechadas> listaFechada = new ArrayList<ItemOSFechadas>();

                ItemOSFechadas a = new ItemOSFechadas("g1","ffff");
                ItemOSFechadas b = new ItemOSFechadas("g1","ffff");
                ItemOSFechadas c = new ItemOSFechadas("g1","ffff");
                ItemOSFechadas d = new ItemOSFechadas("g1","ffff");
                listaFechada.add(a);
                listaFechada.add(b);
                listaFechada.add(c);
                listaFechada.add(d);

                ListAdapterOSFechadas adapterOSFechadas = new ListAdapterOSFechadas(getContext(),listaFechada);
                listOSFechadas = (ListView)view.findViewById(listFechadasOS);
                listOSFechadas.setAdapter(adapterOSFechadas);
            }catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }


}

My intention is to make my JSON return and assemble my entire list view.

Answer 1

I can’t run your code so I’m not sure, but I think your problem is related to your Listview id.

listOSFechadas = (ListView)view.findViewById(listFechadasOS);

I don’t understand why listechadasOs id, since there is no integer(int) with this value.

There are also some mistakes with the View. Try to edit your code as follows:

//Criando variável view
private View view;
//Remova sua LitView da AsyncTask e defina em onCreateView.
@Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    if (view == null) {
        view = inflater.inflate(R.layout.tab_os_fechada,null);
       listOSFechadas = (ListView)view.findViewById(R.id.id_da_listview);
       new SolicitarDados().execute(url);
       }
       return view; 
 }