ANDROID：获取当前GPS位置永远不会调用＆＃34; onLocationChanged＆＃34;

Question

尝试获取当前的经度和纬度。

CODE：

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        LocationListener locationListener = new myLocationListener();
        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1, 1, locationListener);
    }

    class myLocationListener implements LocationListener {
        @Override
        public void onLocationChanged(Location loc) {
            tvLang.setText("");
            Toast.makeText(getBaseContext(), "Location changed: Lat: " + loc.getLatitude() + " Lng: " + loc.getLongitude(), Toast.LENGTH_SHORT)
                    .show();
        }
        @Override
        public void onProviderDisabled(String provider) {
        }

        @Override
        public void onProviderEnabled(String provider) {
        }
        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
        }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

但是当我在LG G2上运行时 - 它永远不会进入＆＃34; onLocationChanged＆＃34;功能。 GPS已开启，我可以在谷歌地图中找到自己。 试图重启手机几次。

我做错了什么？