ztree 后台异步加载_zTree异步加载时，点击父节点没有向后台取数据

js代码：

var curMenu = null, zTree_Menu = null;

var setting = {

async:{

autoParam:["menuid"],//异步加载时自动提交父节点参数

contentType:"application/json",//提交参数的数据类型

enable:true,//是否开启异步加载模式

type:"post",//提交方式

url:"LoadServlet",//服务端加载类

},

view: {

showLine: true,

selectedMulti: false,

dblClickExpand: false

},

data: {

simpleData: {

enable: true,

idKey:"menuid",

pIdKey:"parentid"

}

},

callback:{

asyncSuccess: zTreeOnAsyncSuccess,//异步加载成功的fun

asyncError: zTreeOnAsyncError, //加载错误的fun

beforeClick:beforeClick //捕获单击节点之前的事件回调函数

}

};

function zTreeOnAsyncError(event, treeId, treeNode){ alert("异步加载失败!"); }

function zTreeOnAsyncSuccess(event, treeId, treeNode, msg){ }

function beforeClick(treeId, node) {

if (node.isParent) {

if (node.level === 0) {

var pNode = curMenu;

while (pNode && pNode.level !==0) {

pNode = pNode.getParentNode();

alert(pNode);

}

if (pNode !== node) {

var a = $("#" + pNode.tId + "_a");

a.removeClass("cur");

zTree_Menu.expandNode(pNode, false);

}

a = $("#" + node.tId + "_a");

a.addClass("cur");

var isOpen = false;

for (var i=0,l=node.children.length; i

if(node.children[i].open) {

isOpen = true;

break;

}

}

if (isOpen) {

zTree_Menu.expandNode(node, true);

curMenu = node;

} else {

zTree_Menu.expandNode(node.children[0].isParent?node.children[0]:node, true);

curMenu = node.children[0];

}

} else {

zTree_Menu.expandNode(node);

}

}

return !node.isParent;

}

$(document).ready(function(){

$.fn.zTree.init($("#treeDemo"), setting);

zTree_Menu = $.fn.zTree.getZTreeObj("treeDemo");

});

后台代码(LoadMenuDaoImpl)：

conn=BaseDao.getConn();

String sql="select * from tbl_menu where parentid=?";

ps=conn.prepareStatement(sql);

ps.setString(1, menuid);

rs=ps.executeQuery();

menu.append("[");

while(rs.next()){

menu.append("{menuid:'"+rs.getString("menuid")+"',parentid:'"+rs.getString("parentid")+"',name:'"+rs.getString("menuname")+"',isParent:true},");

}

menu.append("]");

LoadMenuServlet代码：

response.setContentType("text/html;charset=utf-8");

PrintWriter out = response.getWriter();

String menuid=request.getParameter("menuid");

System.out.println(menuid);

if(menuid==null||menuid.equals("")){

menuid="0";

}

LoadMenuDao lmd=new LoadMenuDaoImpl();

String menus=lmd.loadMenu(menuid);

out.print(menus);

out.flush();

out.close();

显示结果：

目前的问题是，菜单的根目录已经加载上来，但是，当我点击父节点的时候，如：数据展示篇，它并没有再次向后台读取数据！没有实现异步！

求解决！