ruby-on-rails - Rails Ruby slect_tag :include_blank 未选择为默认值

Question

 <%= select_tag(:event_type, options_from_collection_for_select(@event_types, 'id', 'name', 1),  { :include_blank => true } ) %> 

这将生成所需的所有选项，但默认情况下不选择空白选择。为什么

Answer 1

方法的第四个参数options_from_collection_for_select是选择值。“1”在你的情况下。利用options_from_collection_for_select(@event_types, 'id', 'name')

options_from_collection_for_select