form_tag

class SwitchesController < ApplicationController
  #before_filter :authenticate_user!, :except => [:index, :show]
  def index
  end

  def show
  end

  #存储拓扑
  def topo
    @vts = VmToSwitch.all
    @sts = SwitchToSwitch.all
    @stvs = SwitchToVswitch.all
  end

  #监控
  def monitor
    @switches = [["S1","s1v"],["S2","s2v"]]
    @select_value = params[:people]
  end

end

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<%= render partial: ‘bar‘ %>
<b>hello monitor</b>
<%= form_tag("monitor") do |f| %>
<%= select_tag "people", options_for_select(@switches), prompt: "Select something" %>
<%= submit_tag("Search") %>
<% end %>
</br>
<b>your choice:</b>
<%= @select_value %>