相关疑难解决方法(0)

我需要从gps获得速度和前进.但是我唯一的号码location.getSpeed()是0或有时不可用.我的代码:

        String provider = initLocManager();
    if (provider == null)
        return false;
    LocationListener locListener = new LocationListener() {
        public void onLocationChanged(Location location) {
            updateWithNewLocation(location, interval, startId);
            Log.i(getString(R.string.logging_tag), "speed =" + location.getSpeed());
        }

        public void onProviderDisabled(String provider){
            updateWithNewLocation(null, interval, startId);
        }

        public void onProviderEnabled(String provider) {}
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    };

    _locManager.requestLocationUpdates(provider, interval,  DEFAULT_GPS_MIN_DISTANCE, locListener);


    private String initLocManager() {
    String context = Context.LOCATION_SERVICE;
    _locManager = (LocationManager) getSystemService(context);

    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    criteria.setAltitudeRequired(false);
    criteria.setBearingRequired(true); …