안드로이드 GPS에서 속도 받기

Question

내 응용 프로그램에서 LocationManager의 속도를 높이고 싶습니다. setSpeedRequired (true) 특성을 가진 기준이 있습니다. 나는 location.getSPeed()를하고 있지만 항상 0을 제공합니다. 아래는 내가 서비스로 실행하고있는 GPS 코드입니다.

public class Tracking extends Service implements LocationListener { 

    protected LocationManager locationManager; 
    Location location; 
    double latitude; 
    double longitude; 
    float velocity; 
    String provider; 

    private static final long minDist = 0; 
    private static final long minTime = 0; 
    LocationDatabaseHandler ldb; 


    @Override 
    public void onCreate() { 
     ldb = new LocationDatabaseHandler(this); 
     getLocation(); 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
    } 

    @Override 
    public void onProviderDisabled(String provider) { 

    } 

    @Override 
    public void onProviderEnabled(String provider) { 

    } 

    @Override 
    public void onStatusChanged(String provider, int status, Bundle extras) { 

    } 

    @Override 
    public IBinder onBind(Intent intent) { 
     return null; 
    } 

    @Override 
    public int onStartCommand(Intent intent, int flags, int startId) { 
     super.onStartCommand(intent,flags,startId); 
     //because we do not want to stop the service unless we explicitly say so. 
     return START_STICKY; 
    } 

    public Location getLocation() { 
     locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     Criteria criteria = new Criteria(); 
     criteria.setSpeedRequired(true); 
     provider = locationManager.getBestProvider(criteria, false); 

     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, minTime, minDist, 
       this); 
     location = locationManager.getLastKnownLocation(provider); 
     if(location != null) { 
      onLocationChanged(location);    
     } 

     return location;   
    } 

    @Override 
    public void onLocationChanged(Location location) { 
     latitude = location.getLatitude(); 
     longitude = location.getLongitude(); 
     batteryP = getBatteryPerc(); 
     velocity = location.getSpeed(); 

     insertIntoDb(latitude, longitude, velocity, "onchanged"); 
    } 

    public void insertIntoDb(double latitude, double longitude, float velocity, String where) { 
     Date date = new Date(); 
     String dateStr = date.toString(); 

     ldb.addLocation(new Locations(latitude, longitude, dateStr, velocity)); 
    } 

} 

데이터베이스를 볼 때 속도는 항상 0.0입니다. 제가 누락 된 것이 있습니까?

Answer 1

locationManager.requestLocationUpdates (provider, minTime, minDist, this);