进度对话框不出现

Question

I have a fragment that, when is pressed a button should show a Progress Dialog and execute a method that contains an AsyncTask but when I press the button, the Progess Dialog does not appear on the screen but the async task is executed. This is the code of the fragment

public class ParcheggiaFragment extends Fragment {

private Button button;
ProgressDialog progressDialog1;
SharedPreferences prefs;
HttpGetNoleggio httpGetNoleggio;

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

    final View layout = inflater.inflate(R.layout.fragment_parcheggia, container, false);

    button = (Button) layout.findViewById(R.id.button);
    prefs = this.getActivity().getSharedPreferences(Keys.SHARED_PREFERENCES, Context.MODE_PRIVATE);
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            progressDialog1.show();

            int a = checkNoleggioCompletato();

            FragmentTransaction fragmentTransaction = getActivity().getSupportFragmentManager().beginTransaction();
            fragmentTransaction.replace(R.id.frame_principale, new ResultFragment());
            fragmentTransaction.commit();

        }
    });

    return layout;
}

private int checkNoleggioCompletato() {

    final int id = prefs.getInt(Keys.ID_UTENTE, -1);

    Integer[] noleggio;
    int idNoleggio = -1;
    try {
        String str = "here i put the url that i have to use" + id; 
        URL url = new URL(str);

        noleggio = httpGetNoleggio.execute(url).get();
        idNoleggio = noleggio[0];
        int idBici = noleggio[1];
        int noleggioResult = idNoleggio;
    } catch (MalformedURLException | ExecutionException | InterruptedException e) {
        e.printStackTrace();
    }
    return idNoleggio;
}

@Override
public void onStart() {

    progressDialog1 = new ProgressDialog(this.getActivity());
    progressDialog1.setIndeterminate(true);

    super.onStart();
}

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    httpGetNoleggio = new HttpGetNoleggio(this.getActivity());

}

@Override
public void onResume() {
    super.onResume();
}

}

The code seems correct and I can't understand why the ProgressDialog does not appear. HttpNoleggio is another class that extends AsyncTask and implements the doInBackground method

Answer 1

As per your code you are displaying the progress bar in ParcheggiaFragment and then replacing this fragment with ResultFragment. As ResultFragment replaced ParcheggiaFragment so that progress bar is not displaying. Just comment the following code:

FragmentTransaction fragmentTransaction = getActivity().getSupportFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.frame_principale, new ResultFragment());
fragmentTransaction.commit();

Then, progressbar will be visible.