试图通过链接调用自定义方法时发生路由错误

嗨,我正试图通过以下链接到erb线路调用我的方法报价:-

<%= link_to "Offer Bid", {:controller => "bids", :action => "offer_bid"},
      :remote => true %>  

但我得到了以下路由错误:-

No route matches {:action=>"offer_bid", :controller=>"bids"}.

我应该在routes.rb文件中显式定义路由吗????

当我运行“rake route s”时,我有如下对应的链接到的路由:-

rake routes | grep bid  
         post_bids GET    /posts/:post_id/bids(.:format)                  {:controller=>"bids", :action=>"index"}  
         post_bids POST   /posts/:post_id/bids(.:format)              {:controller=>"bids", :action=>"create"}
      new_post_bid GET    /posts/:post_id/bids/new(.:format)          {:controller=>"bids", :action=>"new"}
     edit_post_bid GET    /posts/:post_id/bids/:id/edit(.:format)     {:controller=>"bids", :action=>"edit"}
          post_bid GET    /posts/:post_id/bids/:id(.:format)          {:controller=>"bids", :action=>"show"}
          post_bid PUT    /posts/:post_id/bids/:id(.:format)          {:controller=>"bids", :action=>"update"}
          post_bid DELETE /posts/:post_id/bids/:id(.:format)          {:controller=>"bids", :action=>"destroy"}
                          /bids/:bid_id(.:format)                     {:controller=>"bids", :action=>"offer_bid"}    

注意与action=>“offer\u bid”对应的路径名只是一个空白!!! 为什么这里是空白的???
我试图调用的方法如下:-

def offer_bid
   @bid = Bid.find(params[:id])
   @post.bid_winner_id = @bid.user_id
   @post.save
   flash[:notice] = "Task offered to @post.user.email"
end

为实现我的用例所做的任何解释和建议都是非常感谢的。 提前谢谢。

我使用的是rails版本3.01