dataTable增加一个按钮组

sDom: 'rt<"table-footer"<"#table-actions"><"table-pager"ilp>>'

new $.fn.dataTable.Buttons( dataTable, {
                    buttons: [
                        {
                            text: 'Button 2',
                            extend : "selected",
                            action: function ( e, dt, node, conf ) {
                                alert( 'Button 2 clicked on' );
                            }
                        },
                        {
                            text: 'Button 3',
                            extend : "selectedSingle",
                            action: function ( e, dt, node, conf ) {
                                alert( 'Button 3 clicked on' );
                            }
                        }
                    ]
                } );
                dataTable.buttons( 1, null ).container().appendTo(
                    $(dataTable.table().container()).find("#table-actions")
                );