Ext4 Tree读不出来数据，高手帮忙看看哪错了

JScript code

Ext.regModel("TreeMenu",{    fields:[    {name: 'parentid',     type: 'string'},    {name: 'text',     type: 'string'}    ]});var store = new Ext.data.TreeStore({    model:'TreeMenu',    nodeParam:'parentid',  //指定节点参数名    proxy:{        type: 'ajax',        url: 'TreeMenu.aspx',        reader:'json'    },    autoLoad:true,    root:{        text:'根节点',        parentid:'-1'    }});var treenode = Ext.create('Ext.tree.Panel',{       store: store,     columns:[{        xtype:'treecolumn',        dataIndex:'text',        sortable:true    }],    width:250,    height:150,    lines:false,    useArrows : true,    rootVisible:false,    rootVisible: false});

HTML code

[{id:"1",menucode:"xhfp",text:"发票管理",parentid:"0",leaf:false,iconCls:""},{id:"2",menucode:"tjcx",text:"统计查询",parentid:"0",leaf:false,iconCls:""},{id:"3",menucode:"jczl",text:"基础资料",parentid:"0",leaf:false,iconCls:""},{id:"4",menucode:"qxgl",text:"权限管理",parentid:"0",leaf:false,iconCls:""},{id:"5",menucode:"xtsz",text:"系统设置",parentid:"0",leaf:false,iconCls:""}]

C# code

    sorters:[{        property:'text',        direction:'ASC'    }]