手机锁定时更改位置GPS和TextView

Question

我想创建一个应用程序，它会每3秒向scrollview中的textview添加新的经度和纬度。我在手机锁定或应用程序在后台工作时添加新坐标时遇到问题

public class PomiarTrasy extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_pomiar_trasy);
    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    if (lm.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        txt1.setText("Szukanie pozycji...");

    } else {
        txt1.setText("Twój GPS jest wyłączony");

    }

    if (lm.isProviderEnabled(LocationManager.GPS_PROVIDER))
        txt1.setText("Szukanie pozycji...");

    else
        txt1.setText("Twój GPS jest wyłączony");
}

LocationManager lm;
Location savedLocation = null;
LocationListener locationListener = new LocationListener() {

    @SuppressLint("MissingPermission")
    @Override
    public void onLocationChanged(Location location) {

        String latitude = "";
        String longitude = "";

        if (location != null) {

            latitude += location.getLatitude();
            longitude += location.getLongitude();
            txt1.setText("Uzyskano współrzędne!");
        }

        btn_start_zapis.setEnabled(true);

        if (wlacz == 1) {

            txt4.setText(txt4.getText() + "" + location.getLongitude() + ", " + location.getLatitude() + "\n");
            txt5.setText(txt2.getText());
            txt6.setText(txt3.getText());
            txt2.setText(latitude);
            txt3.setText(longitude);
    }

        if (savedLocation == null) {
            savedLocation = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
        }
    }

    @Override
    public void onStatusChanged(String s, int i, Bundle bundle) {

    }

    @Override
    public void onProviderEnabled(String s) {
        txt1.setText("Szukanie pozycji...");
    }

    @Override
    public void onProviderDisabled(String s) {
        txt1.setText("Twój GPS jest wyłączony");
    }
};

任何消化我怎么能这样做？我在背景中了解了Service - GPS工作，但是如何使用TextView？