bootstrap selectpicker

$.ajax({
                type: 'get',
                url: systemConfig.backendurl + '/api/fl/gettype?type=1',
                async: false,
                success: function(res) {
                    if (res.success) {
                        var select = $("#selectwrap");
                        var datas = res.data;
                        for (var i = 0; i < datas.length; i++) {
                            select.append("<option value='" + datas[i].code + "'>" +
                                datas[i].name + "</option>");
                        }
                        $('.selectpicker').selectpicker('val', ['07', '06', '08']);//设置回显值
                        $('.selectpicker').selectpicker('refresh');
                        $('.selectpicker').selectpicker('render');
                        console.log($('.selectpicker').selectpicker('val'));//打印选择的值
                    }
                },
                error: function(err) {
                    console.log(err)
                }
            })

            $('.selectpicker').on('changed.bs.select', function() {//单击时方法
                console.log('agja');
                var val = $(this).val();
                console.log($('.selectpicker').selectpicker('val'));
            });

//html要引入bootstrap.min.js bootstrap-select.min.js bootstrap-select.min.css"
<select class="selectpicker" data-live-search="true" multiple id='selectwrap'></select>