Android Asynctask on PreExecute method not called

Question

I want to start a ProgressDialog when onPreExecute() is called but it is not working.

Homeactivity.java

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

    //switch condtion...
    case R.id.buttontime :                
        new FlightListTask().execute("");
        break:  

}

public class FlightListTask extends AsyncTask<String,ArrayList<HashMap<String, String>>, ArrayList<HashMap<String, String>>> {

    protected String onPreExecute(String temp) {
        progresdialoglistview=ProgressDialog.show(HomeActivity.this, "", "Loading");
        Log.e("onPreExecutive","called"+progresdialoglistview);
        return temp;
    }

    @Override
    protected ArrayList<HashMap<String, String>> doInBackground( String... params ) {
        return flightlist;
    }

    protected void onPostExecute(ArrayList<HashMap<String, String>> flightList) {
        // listview code....
    }

}

Solution 1

Chnge your onPreExecute method as:

  @Override
  protected  void onPreExecute()
  {
      progresdialoglistview=ProgressDialog.show(HomeActivity.this, "","Loading");
      Log.e("onPreExecutive","called"+progresdialoglistview);

  }

onPreExecute() method don't take any parameter and have void return type . so also remove return from onPreExecute

Solution 2

You didn't overrided onPreExecute but overloaded instead.

onPreExecute doesn't takes any params and do not return anything. Use this instead:

protected void onPreExecute()