EXTJS5 做的GroupGrid取值问题

[YY757563246]

GroupGrid取数据库的数据store要怎写呢？
看到网上这样写，但是不行store=new Ext.data.GroupingStore({
proxy:new Ext.data.HttpProxy(
{
url:"DATA/OpenRoomInfo/RoomOpenInfo.aspx",
method:"POST"
}),
reader:new Ext.data.JsonReader(
{
fields:fields,
root:"data",
id:"openroomid",
totalProperty:"totalCount"

}),

看到网上的例子这样写，不过在Extjs5 里好像没有Ext.data.GroupingStore

[fff-cai]

var store = new Ext.data.Store({
            id: "mystore",
            pageSize: pagesize,
            fields: ["ID", "NAME"],
            autoLoad: { start: 0, limit: pagesize },
            proxy: {
                type: 'ajax',
                actionMethods: {
                    create: 'POST',
                    read: 'POST', // by default GET
                    update: 'POST',
                    destroy: 'POST'
                },
                url: '/',
                reader: {
                    type: 'json',
                    rootProperty: 'records',
                    totalProperty: 'total'
                }
            }
        });