Ext4.0.7使用Ext.grid.ColumnModel报错：TypeError: Ext.grid.Model is not a constructor

代码如下：

Ext.onReady(function(){

    　　　　　　　//定义列

                var cm = new Ext.grid.ColumnModel([

                    {header: '编号', dataIndex: 'id'},

                    {header: '名称', dataIndex: 'name'},

                    {header: '描述', dataIndex: 'des'}

                ]);

                

                //数据定义

                var data = [

                    ['1001','name1','description1'],

                    ['1002','name1','description1'],

                    ['1003','name1','description1'],

                    ['1004','name1','description1'],

                    ['1005','name1','description1']

                ];

                

                //数据源定义

                var store = new Ext.data.Store({

                    proxy: new Ext.data.MemoryProxy(data),

                    reader: new Ext.data.ArrayReader({},[

                        {name: 'id'},

                        {name: 'name'},

                        {name: 'des'}

                    ])

                });

                store.load();

                

                //grid panel

                var grid = new Ext.grid.GridPanel({

                    renderTo: Ext.getBody(),

                    store: store,

                    cm: cm

                });

});

google了一下：In Extjs 4.0 ,there is no colModel config for GridPanel(http://www.sencha.com/forum/showthread.php?199720-Ext.grid.ColumnModel-is-not-a-constructor)然后查看其API：其用法如下

Ext.onReady(function(){

　　　　　　　　Ext.create('Ext.data.Store', {

                    storeId: 'simpleStore',

                    fields: ['name', 'email', 'phone'],

                    data:{

                        'items':[

                            {'name':'yanshiying', 'email':'email', 'phone':'1234567890'},

                            {'name':'yanshiying', 'email':'email', 'phone':'1234567890'},

                            {'name':'yanshiying', 'email':'email', 'phone':'1234567890'}

                        ]

                    },

                    proxy: {

                        type: 'memory',

                        reader: {

                            type: 'json',

                            root: 'items'

                        }

                    }    

                });

                

                Ext.create('Ext.grid.Panel', {

                    title: 'Simple',

                    store: Ext.data.StoreManager.lookup('simpleStore'),

                    columns: [

                        {header: 'Name', dataIndex: 'name'},

                        {header: 'Email', dataIndex: 'email'},

                        {header: 'Phone', dataIndex: 'phone'}

                    ],

                    height: 200,

                    width: 400,

                    renderTo: Ext.getBody()

                });

})

运行效果：