Ruby on rails Rails 4回形针头像文件名：无

我的用户模型添加了最新版本的曲别针gem，我从曲别针wiki学习教程

class User < ActiveRecord::Base
 has_attached_file :avatar, :styles => { :medium => "300x300>", :thumb => "100x100>" },    :default_url => "/images/:style/missing.png"
 validates_attachment_content_type :avatar, :content_type => /\Aimage\/.*\Z/

 devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :trackable, :validatable
end

当输入rails c和user=user.all时

avatar_file_name: nil, avatar_content_type: nil, avatar_file_size: nil, avatar_updated_at: nil

---

您是否忘记更改此选项以反映您的用户对象

<%= simple_form_for(resource, as: resource_name, url: registration_path(resource_name),:html => {:multipart => true}) do |f| %>

{:multipart=>true}）do | f |%>

我更新到

{:multipart=>true}do | f |%>

，它有头像文件名：nil，不工作你忘了设置你的url，用户创建后它会去哪里？或者，您可以在控制器“def create@user=user.create（secure_params）@user.save render“show”end”中的创建操作中添加重定向到。这一切都不起作用。请将_重定向到user_url（@user）或任何用户显示的路由。也可以剪切和粘贴您从浏览器或终端收到的消息

<%= simple_form_for(resource, as: resource_name, url: registration_path(resource_name),:html => {:multipart => true}) do |f| %>
 <%= f.error_notification %>

 <div class="form-inputs">
  <%= f.file_field :avatar %>
  <%= f.input :email, required: true %>
  <%= f.input :password, required: true %>
  <%= f.input :password_confirmation, required: true %>
 </div>

 <div class="form-actions">
  <%= f.button :submit, "Sign up" %>
 </div>
<% end %>

<%= render "devise/shared/links" %>

source 'https://rubygems.org'
ruby '2.1.1'
gem 'rails', '4.1.1'
gem 'sqlite3'
gem 'sass-rails', '~> 4.0.3'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.0.0'
gem 'jquery-rails'
gem 'turbolinks'
gem 'jbuilder', '~> 2.0'
gem 'sdoc', '~> 0.4.0',          group: :doc
gem 'spring',        group: :development



gem 'devise'
gem 'simple_form'
gem "paperclip", "~> 4.1"

group :development do
 gem 'better_errors'
 gem 'binding_of_caller', :platforms=>[:mri_21]
 gem 'quiet_assets'
 gem 'rails_layout'
end

avatar_file_name: nil, avatar_content_type: nil, avatar_file_size: nil, avatar_updated_at: nil

<%= simple_form_for(resource, as: resource_name, url: registration_path(resource_name),:html => {:multipart => true}) do |f| %>