用递归实现简单的tree

//
package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.net.URLLoader;
    import flash.net.URLRequest;

    public class TreeExample extends Sprite
    {
        private var _xml:XML;
        private var _strTab:String = "--";
        private var _space:String = "";
        public function TreeExample()
        {
            this.loadXML();
        }
        private function loadXML():void
        {
            var urlLoader:URLLoader = new URLLoader();
            var url:String = "tree.xml";
            urlLoader.addEventListener(Event.COMPLETE, complete_urlLoader);
            urlLoader.load(new URLRequest(url));
        }
        private function complete_urlLoader(evt:Event):void
        {
            this._xml = XML(evt.target.data);
            this.createTree(this._xml);
        }
        /**
         * 递归
         * @param xml
         * 
         */        
        private function createTree(xml:XML):void
        {
            var childList:XMLList = xml.children();
            trace(this._space + xml.@label);
            if(xml.children().length() > 0)
            {
                for (var i:int = 0; i < childList.length(); i++)
                {
                    this._space += this._strTab;
                    this.createTree(childList[i]);
                }
            }
            this._space = this._space.substr(0, this._space.length - 2);
        }
    }
}

 

//

xml文件:

 

<?xml version="1.0" encoding="utf-8" ?>
<data label="">
  <item label="科目">
    <item label="语文">
      <item label="第一个语文课"/>
      <item label="第二个语文课"/>
    </item>
    <item label="数学">
      <item label="第一个数学课">
    <item label="第一个数学课的内容"/>
      </item>
      <item label="第二个数学课"/>
    </item>
  </item>
</data>