easyui datagrid生成序号列formatter

var opts1;

$('#datagrid_1').datagrid({

    columns: [

        [{

                field: 'myNo',

                title: '序号',

                align: 'center',

                width: 100,

                formatter: function (value, row, index) {

                    if (!opts1) {

                        opts1 = $('#datagrid_1').datagrid('options');

                    }

                    return opts1.pageSize * (opts1.pageNumber - 1) + index + 1;

                }

            }

        ]

    ]

});