Android中在OnCreate时获得控件高度

ViewTreeObserver vto = mArrowUp.getViewTreeObserver();vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {    @Override    public void onGlobalLayout() {    mArrowUp.getViewTreeObserver().removeGlobalOnLayoutListener(this);        Log.e("Width",Integer.toString(mArrowUp.getWidth()));            }});