easyui和asp.net mvc问题

[杰拉尔]

$('#test').treegrid({
title: 'TreeGrid',
iconCls: 'icon-save',
width: 700,
height: 350,
nowrap: false,
rownumbers: true,
animate: true,
collapsible: true,
url: "/Admin/getjson",
idField: 'code',


url的JSON没有获取到 这是返回的JSON
[{"UserId":1,"UserName":"2","password":"3"}]