？没明白你的意思

rails view 里面有一个 helper grouped_collection_select def render_topic_node_select_tag(topic) return if topic.blank? grouped_collection_select :topic, :node_id, Rforum::Section.all, :sorted_nodes, :name, :id, :name, :value => topic.node_id, :include_blank => true, :prompt => "选择节点" end