layui 多选下拉框动态赋值后变为单选下拉框？

Question

动态赋值前

动态赋值后

多选效果没了
html

<div class="layui-form-item">
                <label class="layui-form-label">多选</label>
                <div class="layui-input-block">
                    <select multiple="multiple" lay-filter="test" id="tag2">
                        <option value="">请选择</option>
                        <option value="1">1</option>
                        <option value="2">2</option>
                        <option value="3">3</option>
                        <option value="4">4</option>

                    </select>
                </div>
            </div>

js

$.each(data, function (index, value) {
                                $('#tag2').append(new Option(value.content,value.tagid));
                            });

Answer 1

问题已解决。使用了formSelect-v4.js