private fun printAllChild(viewGroup: ViewGroup) {
       val link = LinkedList<ViewGroup>()
       link.add(viewGroup)
       while (!link.isEmpty()){
           val vg = link.poll()
           if (vg!=null){
               for (index in 0 until vg.childCount){
                   val child = vg.getChildAt(index)
                   if (child is ViewGroup){
                       link.add(child)
                   }else{
                       Log.v("zyl__","child = $child")
                   }
               }
           }
       }
   }