Android：如何让我的googleapp在后台运行

Question

如何让这款应用在后台运行？我无法实现Service类，因为我已经使用了MapActivity。我该怎么办？

public class GoogleMaps extends MapActivity implements LocationListener {

    LocationManager locationManager;
    MapView map;

    long start;
    long stop;

    MyLocationOverlay myLocation;
    MapController controller;
    List<Overlay> overlayList;

    int x, y;
    GeoPoint touchedPoint;
    Drawable d;

    String towers;
    int lat;
    int longi;

    double midllat;
    double midlongi;

    NotificationManager nm;
    static final int uniqueID = 1394885;

    // Location location;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.googlemaps);
        map = (MapView) findViewById(R.id.mvGoogleMaps);
        ourLocation();
        Touchy t = new Touchy();
        overlayList = map.getOverlays();
        overlayList.add(t);
        d = getResources().getDrawable(R.drawable.round_pointer);
        controller.setZoom(18);
        Criteria crit = new Criteria();
        towers = locationManager.getBestProvider(crit, false);
        Location location = locationManager.getLastKnownLocation(towers);

        nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        nm.cancel(uniqueID);

    }

    public void ourLocation()

    {
        // Pin der blinker på lokation
        myLocation = new MyLocationOverlay(this, map);
        map.getOverlays().add(myLocation);
        myLocation.enableMyLocation();

        // Fin nuværende lokation
        locationManager = (LocationManager) this
                .getSystemService(Context.LOCATION_SERVICE);
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
                20000, 0, this);

        controller = map.getController();

    }

此处有更多代码，但与此案例无关。只是一个让我能说明问题的功能。

    @Override
    protected void onPause() {
        // TODO Auto-generated method stub
        myLocation.disableCompass();
        super.onPause();
        locationManager.removeUpdates(this);
    }

    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        myLocation.enableCompass();
        super.onResume();
        locationManager.requestLocationUpdates(towers, 500, 1, this);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub
    }

    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub
    }

    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onLocationChanged(Location location1) {
        // TODO Auto-generated method stub
        // Updating location and zoom
        controller.setCenter(new GeoPoint(
                (int) (location1.getLatitude() * 1000000), (int) (location1
                        .getLongitude() * 1000000)));
        controller.setZoom(18);

        // Trying to get MyPostion.
        Location myLocation = new Location("point A");
        myLocation.setLongitude(location1.getLongitude());
        myLocation.setLatitude(location1.getLatitude());
        Location locationB = new Location("point B");
        locationB.setLatitude(midllat);
        locationB.setLongitude(midlongi);

        float distance = myLocation.distanceTo(locationB);

        if (distance < 100) {
            String hej = formatDist(distance);

            AudioManager am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
            am.setRingerMode(AudioManager.RINGER_MODE_SILENT);

            Intent intent = new Intent(this, GoogleMaps.class);
            PendingIntent pi = PendingIntent.getActivity(this, 0, intent, 0);
            String body = "You are now in the silentzone";
            String title = "IRemember";
            Notification n = new Notification(R.drawable.round_pointer, body,
                    System.currentTimeMillis());
            n.setLatestEventInfo(this, title, body, pi);
            n.defaults = Notification.DEFAULT_ALL;
            nm.notify(uniqueID, n);
        }
    }

    public String formatDist(float meters) {
        if (meters < 1000) {
            return ((int) meters) + "m";
        } else
            return formatDec(meters / 1000f, 1) + "km";
    }

    public String formatDec(float val, int dec) {
        int factor = (int) Math.pow(10, dec);
        int front = (int) (val);
        int back = (int) Math.abs(val * (factor)) % factor;
        return front + "." + back;
    }


}