Question

I am calling an AsyncTask to stop an previously started service.
But the ProgressDialog does not rotate while the Asyctask is running.
So I think that there is something wrong and I could get problems with an ANR error.

Any ideas?

new asyncTaskZieladresse().execute();

public class asyncTaskZieladresse extends AsyncTask<Void, Integer, Void> {
    int progress;
    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        final Spinner Fahrerauswahl = (Spinner)findViewById(R.id.spinner1);
        final Spinner Fahrzeugauswahl = (Spinner)findViewById(R.id.spinner2);
        final Spinner Nutzungsartauswahl = (Spinner)findViewById(R.id.spinner3);
        Cursor mcursor = (Cursor) Fahrerauswahl.getSelectedItem();
        Fahrer = mcursor.getString(mcursor.getColumnIndexOrThrow("name"));
        FahrerID = mcursor.getString(mcursor.getColumnIndexOrThrow("_id"));
        mcursor.close();
        Cursor mcursor1 = (Cursor) Fahrzeugauswahl.getSelectedItem();
        Kennzeichen = mcursor1.getString(mcursor1.getColumnIndexOrThrow("fahrzeug_kennzeichen"));
        KennzeichenID = mcursor1.getString(mcursor1.getColumnIndexOrThrow("_id"));
        mcursor1.close();
        Cursor mcursor2 = (Cursor) Nutzungsartauswahl.getSelectedItem();
        Nutzungsart = mcursor2.getString(mcursor2.getColumnIndexOrThrow("nutzungsart"));
        NutzungsartID = mcursor2.getString(mcursor2.getColumnIndexOrThrow("_id"));
        mcursor2.close();
        VariablenUebergebenGpsFahrt();
        progressDialog.dismiss();
    }
    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        progressDialog = ProgressDialog.show(Main.this, "GPS", "Ziel-Standort wird ermittelt...");
    }
    @Override
    protected void onProgressUpdate(Integer... values) {
        // TODO Auto-generated method stub
    } 
    @Override
    protected Void doInBackground(Void... arg0) {
        // TODO Auto-generated method stub
        stopService(new Intent(Main.this, GPSService.class));
        return null;
    }    

}

Answer 1

Thats the reason why I have tried to stop the service with the AsyncTask.

This will not help, as I have tried to explain in the comments to your question. If onDestroy() is taking too long, you need to do that work sooner and in a background thread. Putting the stopService() call in a background thread is completely pointless.

The service itself runs already in the background and not in the UI-thread.

No, it is not.

onDestroy() is called on the main application thread. Always.

Your service might also have a background thread of its own for other work, but the lifecycle methods (onCreate(), onStartCommand(), onBind(), and onDestroy()) are always called on the main application thread.

So if the stopping of the service took a long of time, why is the app hanging?

Because you are doing too much work in onDestroy().

The service and the command that waits for the return of the stopped service are not running in the UI-thread.

onDestroy() is called on the main application thread (a.k.a., “UI-thread”).

---

UPDATE based on first comment:

When I call onDestroy() inside the service

You never call onDestroy(). Android calls onDestroy(). You are not Android.

the onDestroy() is not called inside the service for the service itself, rather in the Main thread?

You seem to think that a service is a thread. It is not. You can tell this by reading the documentation (“Note that services, like other application objects, run in the main thread of their hosting process. “). Please read the documentation.