EXTJS 遍历树

var rootN=Ext.getCmp('treepanel').getRootNode();//获取树的根节点
        function setNodeDrag(cNo,pid){//遍历节点根据panelID查找相应的节点设置draggalbe为true
            var childnodes = cNo.childNodes;//获取根节点的子节点
            for(var i=0; i < childnodes.length; i++){
               var cNode = childnodes[i];
               if(cNode.id == pid)
               {
                 cNode.draggable = true;
               }
               if(cNode.hasChildNodes()){
                 setNodeDrag(cNode,pid);//递归调用
               }
            }
        }

setNodeDrag(rootN,panel.id);//调用函数