scrollview smoothScrollTo不起作用的问题

LinearLayout ll = (LinearLayout) findViewById(R.id.ll);        final ScrollView hsv = (ScrollView) findViewById(R.id.hsv);        OnGlobalLayoutListener listener = new OnGlobalLayoutListener() {            @Override            public void onGlobalLayout() {                hsv.scrollTo(100, 0);            }        };        ll.getViewTreeObserver().addOnGlobalLayoutListener(listener);