= f.text_field :tax_category_id, :value => @invoice.tax_category.name, :class => "form-control js-tax-category-val"
= f.text_field :studno, :class => "form-control"
= text_field_tag "header-even-item", "", :class => "btn-select-input btn-select-value header-even-text", :"data-selected" => ""
原文：https://www.cnblogs.com/znsongshu/p/9742928.html