Flex中删除Tree的节点

//删除菜单节点
    private function deleteMenuItem(event:Event):void
    {
     var xml:XML = _mainPortal.myTree.selectedItem as XML;
     
      if( xml == null ) return;
      //删除菜单节点的子节点
      deleteChildren(xml);
 
      if(xml.parent().hasOwnProperty("node") == true)
      {
       var parentxml:XML=xml.parent() as XML;
         for(var i:uint;i<parentxml.child("node").length();i++)
         {
         if(parentxml.child("node")[i]==xml[0])
    {
     delete parentxml.children()[i];
    }
         }
      }
      else
      {
       Alert.show("新添加的节点才能删除！","系统提示");
      }
    }

 

 //删除子节点
    private function deleteChildren(parentxml:XML):void
    {
     var xml:XML = parentxml;
     
      if( xml == null ) return;
      if(xml.hasOwnProperty("node") == true)
      {
       for(var i:uint=0; i<xml.child("node").length();i++)
       {
         delete xml.children()[i];
       }
      }     
    }

 

<mx:Button label="删除" click="deleteMenuItem(event)"/>