android get adMob banner height when appears

I am adding an adMob banner to my app successfully. When banner appears I need to get its height in order to resize all layout elements. I am using the event onReceivedAd, that is properly fired. However, alturaBanner is = 0. Then, how to get its height? thank you.

   /** Called when an ad is received. */
    @Override
    public void onReceiveAd(Ad ad) 
    {
        adView.setVisibility(View.VISIBLE);

        int alturaBanner = adView.getHeight();

        RelativeLayout.LayoutParams params1 = (android.widget.RelativeLayout.LayoutParams) browse2
        .getLayoutParams();

        params1.setMargins(0, alturaBanner, 0, 0);

      Log.d(LOG_TAG, "onReceiveAd");
      Toast.makeText(this, "onReceiveAd", Toast.LENGTH_SHORT).show();
    }