ruby-on-rails-3 – 在Rails 3.1 RC中相当于File.read(Rails.roo

email_banner = File.read(Rails.root.join('public/images/email_banner.png'))

由于Rails 3.1 RC将图像dir移动到app / assets / images,我得到错误：

Errno::ENOENT: No such file or directory - /Users/Foo/Sites/foobar/public/images/email_banner.png

我如何在Rails 3.1 RC中使用它？

供您参考,我的UserMailer类的代码块：

class UserMailer < ActionMailer::Base
  default :from => "from@example.com"

  def verification_email(user_id)
    @user = User.find(user_id)
    @verification_url = verification_url(:id => @user.verification_code)

    email_banner = File.read(Rails.root.join('public/images/email_banner.png'))
    attachments.inline['email_banner.png'] = email_banner

    mail(:from => "Foobar <support@foobar.com>",:to => "#{@user.full_name} <#{@user.email}>",:subject => 'Foobar Verification Email')
  end
....

我可以使用asset_path吗？