我的环境：

ruby   2.3.3
Rails   5.0.2
centos  7.1

这是我的 comment（评论）controller

class CommentsController < ApplicationController
  before_action :authenticate_user!, only: [:new, :destroy]


  def new
    @user = User.find(current_user) #当前用户
    @group = @user.group.find params[:group_id]
    @comment = Group.comment.new
  end

  def create
    #@content = commentabel_record.comment.create params[:comment]
    @user = User.find(current_user) #当前用户
    @group = @user.group.find params[:group_id]

    @comment = @group.comments.build params[:comment]
    @comment.user = @user


    if @comment.save
      redirect_to commentabel_record, notice: '创建评论成功'
    else
      redirect_to commentabel_record, notice: '创建评论失败'
    end
  end

  def destroy
    @comment = commentable_record.comments.find(params[:id])
    if @comment.user == current_user or current_user.id == 1
      @comment.destroy
    end

    redirect_to commentable_record, :notice => '成功删除评论 '
  end


  protected
  def commentable_record
    Group.find(params[:group_id])
  end
end

这是我的 group（话题）的 show 页面

<div class="container">
  <div class="row">
    <div class="col-md-8">
      <div id="main-content">
        <p><%= markdown(@group.title)%></p>
        <p><%= markdown(@group.description) %></p>
      </div>
      <%= link_to '编辑', edit_group_path(@group)%>
      <%= link_to '删除', group_path(@group),
        method: :delete,
        data: {confirm: '确定删除该话题?'}
      %>
    </div>
      <!-- 显示话题评论 -->
      <%= render @group.comments %>
      <!--  评论表单-->
      <div class="comment-area">
        <%= render 'comments/form' %></br>
      </div>
    </div>
  </div>
</div>

这是我的 comment（评论）_form.html.erb

<% if user_signed_in? %>
  <%= form_for [@group, @groups.comments.build] do  |f| %>

    <div class="field">
      <%= f.label :评论 %></br>
      <%= f.kindeditor :commenter %>
    </div>
      <%= hidden_field_tag(:group_id, @group.id) %>

    <div class="actions">
      <%= f.submit "提交"%>
    </div>
    <% end %>
  <% else %>
    <%= link_to "登录后可以添加评论", new_user_session_path %></br>
  <% end %>

这是我的 group.rb

class Group < ActiveRecord::Base
  belongs_to :user
  validates :title, presence: true

  has_many :comments

  has_many :group_relationships
  has_many :members, through: :group_relationships, source: :user

  default_scope  { order(created_at: 'DESC') } # order: 'articles.created_at DESC'
end

这是我的 comment.rb

class Comment < ActiveRecord::Base
  belongs_to :group
  belongs_to :user

  default_scope  { order(created_at: 'DESC') } # order: 'comments.created_at DESC'

end

这是我的 routes

Rails.application.routes.draw do

  devise_for :users

  root 'groups#index'

  resources :groups do
    member do
      post :comments
    end
  end
end

comment 表中 有 commenter user_id group_id 这些字段

这是报错信息：

在这之前一直报错 comment 参数不能为空或 niu 怎么试 都是这个错误 然后我看了 guides（http://guides.ruby-china.org/getting_started.html#creating-the-blog-application ）然后修改了_form.html.erb 然后就报现在的错。 我项目的代码地址： https://github.com/babyhai/makeyuan 还请各位朋友帮忙看看