select2 没有 allowClear 不生效

select2 没有 allowClear 不生效

image.png

添加：

placeholder: "请选择",
placeholderOption: "first",

$("[name=deptNo]").html(appList.departmentHtml).select2({
    placeholder: "请选择",
    placeholderOption: "first",
    allowClear: true
});