TreeGrid数据不显示?报错

TreeGrid数据不显示，js也没有报错。不知道原因。

$('#test2').treegrid({
		url: '../../PurSelectGoodsCTL/CalculatePlanInfo?calculate='+ss.toString(),
		title: 'TreeGrid - ContextMenu',
		width: 1200,
		height: 500,
		fitColumns: true,
		rownumbers: true,
		idField:'id',
		treeField:'物料编码',
		columns:[[
			{field:'物料编码',title:'物料编码',width:80},
			{field:'物料名称',title:'物料名称',width:120},
			{field:'物料规格',title:'物料规格',width:120},
			{field:'计量单位',title:'计量单位',width:30,align:'right'},
			{field:'单位用量',title:'单位用量',width:30,align:'right'},
			{field:'库存数量',title:'库存数量',width:30,align:'center'},
			{field:'备注',title:'备注',width:60,align:'center'},
			{field:'物料编码bom',title:'物料编码bom',width:60,align:'center'}
		]]
	});

这个数据格式我是参考easyui  demo里的treegrid_data3.json的数据格式写的。

{"total":117,"rows":[
	{"id":1,"code":"code1","name":"name1","addr":"address1"},
	{"id":11,"code":"code11","name":"name11","addr":"address11","_parentId":1},
	{"id":2,"code":"code2","name":"name2","addr":"address2","state":"closed"},
	{"id":21,"code":"code21","name":"name21","addr":"address21","_parentId":2},
	{"id":22,"code":"code22","name":"name22","addr":"address22","_parentId":2},
	{"id":3,"code":"code3","name":"name3","addr":"address3","state":"closed"}
]}

问题出在哪里啊？