使用计时器更新listview的项目和子项目

I would like to update some or all of my listview's items and subitems contents with a timer (1 second refresh) But the listview flicker each one second. Sometimes the subitems are lost during redrawing. Because my listview contains data that is to be likely changed anytime, I use a timer.I would like to update some or all of my listvi