Rails collection_select + bootstrap 下拉菜单

Question

<div class="dropdown">
...
 <%= ff.collection_select :vendor_id, @vendors, :id, :vendor, :include_blank => true, class: "dropdown-menu" %> 
...
</div>

我有一个表单，然后我使用如上所示的 fields_for 来收集输入。但是我看不到here 所示的程式化引导下拉菜单。我应该进行哪些更改才能看到引导风格化的下拉菜单？

Answer 1

来自

<%= ff.collection_select :vendor_id, @vendors, :id, :vendor, :include_blank => true, class: "dropdown-menu" %>

到

<%= ff.collection_select :vendor_id, @vendors, :id, :vendor, {:include_blank => true}, {class: "dropdown-menu"} %>

collection_select(object, method, collection, value_method, text_method, options = {}, html_options = {})