RegistrationsController#create 中的 ActionControllerInvalidAuthenticityToken

标题：解析 ActionController::InvalidAuthenticityToken 错误

ruby
class RegistrationsController < ApplicationController
  before_action :authenticate_user, only: [:create]
  def create
    # Your code for user registration
    if user.save
      redirect_to root_path, notice: "用户注册成功！"
    else
      flash[:error] = "用户注册失败！"
      render :new
    end
  end
  rescue_from ActionController::InvalidAuthenticityToken do |exception|
    redirect_to root_path, alert: "出现了一个错误，请重试。"
  end
end