使用虚拟列表时,每次查完数据之后要调用SetItemCount,则这会引起控件刷新,造成闪烁,应该调用
 SetItemCountEx(100,LVSICF_NOSCROLL|LVSICF_NOINVALIDATEALL);
   LVSICF_NOINVALIDATEALL   The list view control will not repaint unless affected items are currently in view. This is the default value.
   LVSICF_NOSCROLL   The list view control will not change the scroll position when the item count changes. 
   但是,LVSICF_NOSCROLL在有皮肤存在时是无效的,会在滚动条位置引起轻微的闪烁.