递归打开tree的第一个结点

tree.addEventListener(TreeEvent.ITEM_OPEN,onTreeOpen);//监听tree的ITEM_OPEN事件

 

private function onTreeOpen(evt:TreeEvent):void {
 var node:XML = XML(evt.item);
 treeNodeOpen(node);
 return ;
}

 

private function treeNodeOpen(node:XML):void {
 if (node.children().length()>0) {//还有孩子结点,则继续打开孩子结点
  tree.expandItem(node,true,true,true);
  treeNodeOpen(node.children()[0]);
 } else {//其它操作
  
 }
 return ;
}