报的错是在renderHeader的时候cm.rows的rows为空，
请各路大侠帮忙，我该怎么弄才能实现reconfigure
附上代码
var cityGroupRow =[
{header: '<p>adfdfd<p/>', colspan: 4, align: 'center'}];
var continentGroupRow = [
{header: '', colspan: 1, align: 'center'},
{header: '', colspan: 1, align: 'center'},
{header: '资源统计', colspan: 2, align: 'center'}
];
var group = new Ext.ux.grid.ColumnHeaderGroup({
rows: [cityGroupRow,continentGroupRow]
});
var fields =[
{type: 'string', name: 'BeijingProductX'},
{type: 'string', name: 'BeijingProductY'},
{type: 'string', name: 'TokyoProductY'},
{type: 'string', name: 'BerlinProductX'}
];
var columns=[
{dataIndex: 'BeijingProductX', header: 'aaa'},
{dataIndex: 'BeijingProductY', header: 'bbb'},
{dataIndex: 'TokyoProductY', header: 'ccc'},
{dataIndex: 'BerlinProductX', header: 'ddd'}
];
var rd=new Ext.data.JsonReader({
//从那里开始解析你的数据，参数必须的有的root，fields
totalProperty:'total',
root:'root',
fields:fields
});
var store=new Ext.data.JsonStore({
//需要访问的url地址
url: 'Highrailgrid_query.action',
baseParams :{
startTime : startTime,
railIdList : railIdList,
counterParentId : counterParentId,
counterIdList : counterIds
},
reader: rd
});
var grid = new Ext.grid.GridPanel({
id:'grid',
title: 'tt,
width: 1000,
height: 400,
store: store,
columns: columns,
viewConfig: {
forceFit: true
},
plugins: group
});
