使用服务在后台进行 GPS 跟踪

Question

我有一个用于监听 GPS 位置的服务，我想在 Toast 中显示更新的位置，我通过单击按钮在其他活动中运行该服务。该服务已成功创建，但未显示更新位置的 toast。这是代码：

   public class locationlistening_service extends Service implements LocationListener  {

    static LocationManager locationManager;
    LocationListener locationListener;

    private static final String TAG = "Calculations";
    @Override
    public void onCreate() {
        Toast.makeText(this, "My Service Created", Toast.LENGTH_LONG).show();
        Log.d(TAG, "onCreate");
        run();
    }

    private void run(){

        final Criteria criteria = new Criteria();

        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        criteria.setSpeedRequired(true);
        criteria.setAltitudeRequired(false);
        criteria.setBearingRequired(false);
        criteria.setCostAllowed(true);
        criteria.setPowerRequirement(Criteria.POWER_LOW);
        //Acquire a reference to the system Location Manager
        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        // Define a listener that responds to location updates
        locationListener = new LocationListener() {
              public void onLocationChanged(Location location) 
              {
                 recordLocation(location);
              }

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

              public void onProviderEnabled(String provider) {}

              public void onProviderDisabled(String provider) {}

        };
    }
public void recordLocation(Location loc) 
{
Toast.makeText(locationlistening_service.this,"Lat: " + String.valueOf(loc.getLatitude()) + " Long: " + String.valueOf(loc.getLongitude()),Toast.LENGTH_SHORT).show();

}



    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub

    }

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

    }

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

    }



    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }

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

    }

        }

其他活动中有服务调用。

public void startButton(View view) {

    startService(new Intent(this, locationlistening_service.class));
}

Answer 1

您永远不会调用 requestLocationUpdates()。因此，没有任何内容使用您的 LocationManager、LocationListener 或 Criteria。

当不再需要该服务时，请务必关闭该服务。