#2 楼 @Ryan 恩，十分感谢你们的帮助！谢谢！这段时间在准备考试，没鼓捣！问题就搁置了！万分抱歉！ #3 楼 @reyesyang 恩，十分感谢你们的帮助！谢谢！这段时间在准备考试，没鼓捣！问题就搁置了！万分抱歉！

我的模型是这样的：
用户表：Users has_one : cart 购物车表：Carts belongs_to :user (表中通过 user_id 关联) 用户表与购物车表为一对一的关系。 之后对于购物车与商品之间我才用多对多，通过关系表连接 购物车表：has_many :line_items 商品表：has_many :line_items 关系表：belongs_to :flower belongs_to :cart | id | user_id | created_at | updated_at | +----+---------+---------------------+---------------------+ | 4 | NULL | 2013-10-09 09:19:30 | 2013-10-09 09:19:30 | 似乎这个方法需要修改，我一直没能该对 def current_cart Cart.find(session[:cart_id]) rescue ActiveRecord::RecordNotFound cart = Cart.create session[:cart_id] = cart.id cart end 因为当购物车 cart 为空时，就会报错。可能是由于 cart 模型验证，user_id 为空，cart 没能建立。但奇怪的是 line_items 表中数据会写入，此时 cart_id 为空。 控制器代码 cart_controller.rb def create @cart = Cart.new(cart_params) respond_to do |format| if @cart.save format.html { redirect_to @cart, notice: 'Cart was successfully created.' } format.json { render action: 'show', status: :created, location: @cart } else format.html { render action: 'new' } format.json { render json: @cart.errors, status: :unprocessable_entity } end end end def cart_params params.require(:cart).permit(:user_id) # :cart.user_id = current_user.id

end line_items_controller.rb def create @cart = current_cart # @cart = Cart.new() flower = Flower.find(params[:flower_id]) @line_item = @cart.add_flower(flower.id) # @line_item = @cart.line_items.build(:flower => flower)

if @line_item.save redirect_to @line_item.cart # redirect_to flowers_url else render 'new' end end

不知道你这个问题解决没有，我也遇到类似问题。mlb0903 @Teddy

#10 楼 @lmorenbit 还是非常感谢你的帮助！

#6 楼 @lmorenbit 服务器就不定的处理这个问题，重复的！

User Exists (0.4ms)  SELECT 1 AS one FROM `users` WHERE (`users`.`email` = '[email protected]' AND `users`.`id` != 8) LIMIT 1
  SQL (0.3ms)  UPDATE `users` SET `photo_updated_at` = '2013-10-07 02:53:52', `updated_at` = '2013-10-07 02:53:52', `photo_file_name` = 'nightmash.jpg' WHERE `users`.`id` = 8
Command :: identify -format '%wx%h,%[exif:orientation]' '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: convert '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]' -crop 295x295+200+115 -auto-orient -resize "300x300>" '/tmp/nightmash20131007-11429-10t8ohw20131007-11429-faee8k'
Command :: file -b --mime '/tmp/nightmash20131007-11429-10t8ohw20131007-11429-faee8k'
Command :: identify -format '%wx%h,%[exif:orientation]' '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: convert '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]' -crop 295x295+200+115 -auto-orient -resize "100x100>" '/tmp/nightmash20131007-11429-10t8ohw20131007-11429-td1rv4'
Command :: file -b --mime '/tmp/nightmash20131007-11429-10t8ohw20131007-11429-td1rv4'
Command :: identify -format '%wx%h,%[exif:orientation]' '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: identify -format %m '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]'
Command :: convert '/tmp/nightmash20131007-11429-10t8ohw.jpg[0]' -crop 295x295+200+115 -auto-orient -resize "500x500>" '/tmp/nightmash20131007-11429-10t8ohw20131007-11429-9vm6w8'
Command :: file -b --mime '/tmp/nightmash20131007-11429-10t8ohw20131007-11429-9vm6w8'
[paperclip] deleting /home/dreamcity/rails_project/flowerstore/public/assets/products/8/original/nightmash.jpg
[paperclip] deleting /home/dreamcity/rails_project/flowerstore/public/assets/products/8/medium/nightmash.jpg
[paperclip] deleting /home/dreamcity/rails_project/flowerstore/public/assets/products/8/thumb/nightmash.jpg
[paperclip] deleting /home/dreamcity/rails_project/flowerstore/public/assets/products/8/large/nightmash.jpg
  User Exists (0.3ms)  SELECT 1 AS one FROM `users` WHERE (`users`.`email` = '[email protected]' AND `users`.`id` != 8) LIMIT 1
  SQL (0.3ms)  UPDATE `users` SET `photo_updated_at` = '2013-10-07 02:53:53', `updated_at` = '2013-10-07 02:53:52', `photo_file_name` = 'nightmash.jpg' WHERE `users`.`id` = 8

#6 楼 @lmorenbit 刚学两个多月，我再鼓捣鼓捣！！

#6 楼 @lmorenbit 非常感谢，问题解决了部分！现在是裁剪实现了，但是服务器会崩溃.....如果还是将这四个参数传过去的话，重启之后还是崩！只有删掉，会正常。而且图片裁剪爱成功了！

#3 楼 @hooopo 是这样，因为我对值的传递还是理解不够！比如说，我对用户信息更改，似乎只在 new.html.erb 和 edit.html.erb 中成功，其它的页面，更改之后提交，数据库完全没变化！是不是与控制器中的方法有关？

#2 楼 @shatle 有裁剪参数啊，但没传过去，因为裁剪后还是原图！