Ruby on rails 3 Rails错误：nil:NilClass的未定义方法“attribute\u methods\u generated？”

错误：

代码是一个简单的代码，用于允许某人注册。在控制器中创建@tutor对象。每当我删除的表单_时，页面都会很好地加载，但似乎没有其他东西可以修复它

代码：

undefined method `attribute_methods_generated?' for nil:NilClass

这是辅导课：

activesupport (3.0.10) lib/active_support/whiny_nil.rb:48:in `method_missing'
activerecord (3.0.10) lib/active_record/attribute_methods.rb:51:in `respond_to?'
actionpack (3.0.10) lib/action_view/helpers/form_helper.rb:329:in     `apply_form_for_options!'
actionpack (3.0.10) lib/action_view/helpers/form_helper.rb:313:in `form_for'
app/views/tutors/register.html.erb:3:in      `_app_views_tutors_register_html_erb__142383781_2257394860_0'
actionpack (3.0.10) lib/action_view/template.rb:135:in `send'
actionpack (3.0.10) lib/action_view/template.rb:135:in `render'
activesupport (3.0.10) lib/active_support/notifications.rb:54:in `instrument'
actionpack (3.0.10) lib/action_view/template.rb:127:in `render'
actionpack (3.0.10) lib/action_view/render/rendering.rb:59:in `_render_template'
activesupport (3.0.10) lib/active_support/notifications.rb:52:in `instrument'
activesupport (3.0.10) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (3.0.10) lib/active_support/notifications.rb:52:in `instrument'
actionpack (3.0.10) lib/action_view/render/rendering.rb:56:in `_render_template'
actionpack (3.0.10) lib/action_view/render/rendering.rb:26:in `render'
actionpack (3.0.10) lib/abstract_controller/rendering.rb:115:in `_render_template'
actionpack (3.0.10) lib/abstract_controller/rendering.rb:109:in `render_to_body'
actionpack (3.0.10) lib/action_controller/metal/renderers.rb:47:in `render_to_body'
actionpack (3.0.10) lib/action_controller/metal/compatibility.rb:55:in `render_to_body'
actionpack (3.0.10) lib/abstract_controller/rendering.rb:102:in `render_to_string'

---

我明白了。我把课堂作为桌子上的一行

---

谢谢你的帮助

您是否100%确定表格中的@tutor不是零？这可能就是它这么做的原因。另外，在代码中有一个随机]字符，大约是下降的3/4。这个错误的堆栈跟踪是什么？我不知道这怎么会发生。我肯定@tutor不是零。刚刚在上面添加了stacktrace。家教课是什么样子的？里面真的什么都没有。我在这件事上完全被难住了。

activesupport (3.0.10) lib/active_support/whiny_nil.rb:48:in `method_missing'
activerecord (3.0.10) lib/active_record/attribute_methods.rb:51:in `respond_to?'
actionpack (3.0.10) lib/action_view/helpers/form_helper.rb:329:in     `apply_form_for_options!'
actionpack (3.0.10) lib/action_view/helpers/form_helper.rb:313:in `form_for'
app/views/tutors/register.html.erb:3:in      `_app_views_tutors_register_html_erb__142383781_2257394860_0'
actionpack (3.0.10) lib/action_view/template.rb:135:in `send'
actionpack (3.0.10) lib/action_view/template.rb:135:in `render'
activesupport (3.0.10) lib/active_support/notifications.rb:54:in `instrument'
actionpack (3.0.10) lib/action_view/template.rb:127:in `render'
actionpack (3.0.10) lib/action_view/render/rendering.rb:59:in `_render_template'
activesupport (3.0.10) lib/active_support/notifications.rb:52:in `instrument'
activesupport (3.0.10) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (3.0.10) lib/active_support/notifications.rb:52:in `instrument'
actionpack (3.0.10) lib/action_view/render/rendering.rb:56:in `_render_template'
actionpack (3.0.10) lib/action_view/render/rendering.rb:26:in `render'
actionpack (3.0.10) lib/abstract_controller/rendering.rb:115:in `_render_template'
actionpack (3.0.10) lib/abstract_controller/rendering.rb:109:in `render_to_body'
actionpack (3.0.10) lib/action_controller/metal/renderers.rb:47:in `render_to_body'
actionpack (3.0.10) lib/action_controller/metal/compatibility.rb:55:in `render_to_body'
actionpack (3.0.10) lib/abstract_controller/rendering.rb:102:in `render_to_string'

 class Tutor < ActiveRecord::Base
    belongs_to :branch


 end