anchor.diff:    If we ran the app right now and changed every Hero model property, the form might display like this:
     
     如果现在我们运行本应用，并且修改Hero模型的每一个属性，表单看起来像这样：
  +  
   figure.image-display
     img(src="/resources/images/devguide/forms/ng-model-in-action-2.png" width="400px" alt="ngModel in super action")
   :marked
  
positive.code: .l-main-section
  :marked
    ## Conclusion
    ## 结论
  
    The Angular 2 form discussed in this chapter takes advantage of the following framework features to provide support for data modification, validation and more:
    
    从本章对Angular 2表单的讨论中得到的用来支持数据修改、验证等的框架高级特性如下：
  
    - An Angular HTML form template.
    - Angular HTML表单模板。
    - A form component class with a `Component` decorator.
    - 带有`Component`装饰器的组件类。
    - The `ngSubmit` directive for handling the form submission.
    - 用来处理表单提交的`ngSubmit`指令。
    - Template reference variables such as `#heroForm`, `#name`, `#alter-ego` and `#power`.
    - 模板引用变量，如`#heroForm`、`#name`、`#alter-ego`和`#power`。
    - The `[(ngModel)]` syntax for two-way data binding.
    - 用于双向数据绑定的`[(ngModel)]`语法
    - The `ngControlName` directive for validation and form element change tracking.
    - 用于验证和表单元素变化跟踪的`ngControlName`指令
    - The reference variable’s `valid` property on input controls to check if a control is valid and show/hide error messages.
    - 指向input控件的引用变量上的`valid`属性，可用于检查控件是否有效、是否显示/隐藏错误信息。
    - Controlling the submit button's enabled state by binding to `NgForm` validity.
    - 通过绑定到`NgForm`的有效性状态，控制提交按钮的禁用状态。
    - Custom CSS classes that provide visual feedback to users about invalid controls.
    - 对无效控件，定制CSS类来给用户提供视觉反馈。
  
    Our final project folder structure should look like this:
    
    我们最终的项目目录结构看起来是这样：
  .filetree
    .file angular2-forms
    .children
  
negative.code:     只有三处修改：
  
      1. We import the new `HeroFormComponent`.
      
      1. 导入了新的`HeroFormComponent`组件。
  
      1. The `template` is simply the new element tag identified by the component's `selector` property.
      
      1. 直接把`template`的内容改成`HeroFormComponent`的`selector`属性中指定的新元素标签。
  
      1. The `directives` array tells Angular that our template depends upon the `HeroFormComponent`
      which is itself a Directive (as are all Components).
      
      1. `directives`数组告诉Angular，我们的模板依赖于`HeroFormComponent`组件，它本身也是一个指令（所有组件都是指令）。
  
  .l-main-section
  :marked
    ## Create an initial HTML Form Template
    
    ## 创建一个初始的HTML表单模板
  
    Create a new template file called `hero-form.component.html` and give it the following definition:
  