Ruby on rails 获取控制器rails中的select标记值

大家好，我不知道如何在视图中使用select标记并在rails的控制器中获取所选值。我试过一些东西，但没有结果。请有人帮帮我。提前谢谢

index.html.erb

    <%=form_for :law, url: display_lawyers_path do |l|%>

      <h3>Enter the Location</h3>
      <%= l.select(:loc,  options_for_select(@city.collect {|c| [c.Location, c.id]}))%>

      <h3>Enter the Service</h3>
      <%= l.select(:ser, options_for_select(@service.collect{|s| [s.Service_Name, s.id]}))%>

      <div>
        <%= l.submit :submit %>
      </div>

  <%end%>

---

你的实际问题是什么？当我执行“渲染文本：@loc”时，我会看到一个空白屏幕。我正在等待所选的位置。

def index
  @city = Lawyerscitylist.select(:Location).uniq
  @service = Lawyersservicelist.select(:Service_Name).uniq
end

def display
  @loc =  params[:law][:loc]
  render text: @loc
end