public virtual void OnScrollStateChanged(AbsListView view, ScrollState scrollState)
        {
            if (OnScrollListenerDelegate == null)
            {
                return;
            }

            OnScrollListenerDelegate.OnScrollStateChanged(view, scrollState);
        }
        public virtual void OnScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
        {
            if (OnScrollListenerDelegate != null)
            {
                OnScrollListenerDelegate.OnScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
            }

            if ((int)Build.VERSION.SdkInt >= 8)//FROYO
            {
                ScrollChanged(firstVisibleItem);
            }
        }