Android Speicherort getBearing() gibt immer 0 zurück

Habe ich versucht zu implementieren, die eine Funktion für mein Android-app um die Geschwindigkeit und Fahrtrichtung des Geräts, egal wo das Gerät gerichtet ist. Zum Beispiel: Wenn ich mein Android-Gerät ist, wies in Richtung Norden und wenn ich rückwärts in die Süd-Richtung, würde es wieder, dass ich bin bewegt in Richtung Süden.

Ich habe auf der Suche um und ich kam mit einer Möglichkeit, die Lage ist getBearing () - Methode (immer Noch, ich weiß nicht, ob das zu lösen, wird mein ganzes problem). Wenn ich rufe getBearing(), es gibt immer 0.0 aus irgendeinem Grund. Ich habe keine Ahnung, warum. Hier ist mein code:

LocationManager lm;
@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_gcm);
    setUpUI(findViewById(R.id.LinearLayout1));
    isRegged = false;

    //GCM startup
    gcm = GoogleCloudMessaging.getInstance(this);
    context = getApplicationContext();

    gps = new GPSTracker(context);
    //gps.startListening(context);
    //gps.setGpsCall(this);

    /*
     * Variables to indicate location and device ID
     */
    TelephonyManager telephonyManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);

    if (gps.getIsGPSTrackingEnabled())
    {
        longitude = Double.valueOf(gps.getLongitude()).toString();
        latitude = Double.valueOf(gps.getLatitude()).toString();
    }

    deviceID = telephonyManager.getDeviceId();

    mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, (float) 0.0,
            this);
}

Dies ist, wo ich bin immer das Lager.

@Override
public void onLocationChanged(Location currentLocation)
{
    float speed = 0;
    float speed_mph = 0;

    if (previousLocation != null)
    {
        float distance = currentLocation.distanceTo(previousLocation);

        //time taken (in seconds)
        float timeTaken = ((currentLocation.getTime() - previousLocation
                .getTime()) / 1000);

        //calculate speed
        if (timeTaken > 0)
        {
            speed = getAverageSpeed(distance, timeTaken);
            speed_mph = (float) (getAverageSpeed(distance, timeTaken) / 1.6);
        }

        if (speed >= 0)
        {
            info_text.setVisibility(View.VISIBLE);
            info_text_mph.setVisibility(View.VISIBLE);

            DecimalFormat df = new DecimalFormat("#.#");
            info_text.setText("Speed: " + df.format(speed) + " " + "km/h");
            info_text_mph.setText("  Speed: " + df.format(speed_mph) + " "
                    + "mph");

            if (speed >= 10 && lm.getProvider(LocationManager.GPS_PROVIDER).supportsBearing())
            {
                float degree = currentLocation.getBearing();

                direction_text.setVisibility(View.VISIBLE);

                Log.i(TAG, String.valueOf(degree));

                if (degree == 0 && degree < 45 || degree >= 315
                        && degree == 360)
                {
                    direction_text.setText("You are: Northbound");
                }

                if (degree >= 45 && degree < 90)
                {
                    direction_text.setText("You are: NorthEastbound");
                }

                if (degree >= 90 && degree < 135)
                {
                    direction_text.setText("You are: Eastbound");
                }

                if (degree >= 135 && degree < 180)
                {
                    direction_text.setText("You are: SouthEastbound");
                }

                if (degree >= 180 && degree < 225)
                {
                    direction_text.setText("You are: SouthWestbound");
                }

                if (degree >= 225 && degree < 270)
                {
                    direction_text.setText("You are: Westbound");
                }

                if (degree >= 270 && degree < 315)
                {
                    direction_text.setText("You are: NorthWestbound");
                }

            }

        }
    }
    previousLocation = currentLocation;

}

Vielen Dank!