anchor.diff:    The peek-a-boo exists to show how Angular calls the hooks in the expected order.
     
     你可能很少、或者永远不会像这里一样实现所有这些接口。
  -  我们之所以在peek-a-boo中这么做，只是为了观看Angular是如何按照期望的顺序调用这些钩子的。
  -  
  -  In this snapshot, we clicked the *Create...* button and then the *Destroy...* button.
  -  
  -  在下面这个快照中，我们先点击了*Create...*按钮，然后点击了*Destroy...*按钮。
  -  
  +  我们之所以在peek-a-boo中这么做，只是为了观看Angular是如何按照期望的顺序调用这些钩子的。   
   
     This snapshot reflects the state of the log after the user clicked the *Create...* button and then the *Destroy...* button.
  +
  +  用户点击**Create...**按钮，然后点击**Destroy...**按钮后，日志的状态如下图所示：
   figure.image-display
     img(src="/resources/images/devguide/lifecycle-hooks/peek-a-boo.png" alt="Peek-a-boo")
   :marked
  
positive.code:   tr(style=top)
      td ngAfterContentInit
      td
        :marked        
          Respond after Angular projects external content into the component's view.
          
          当把内容投影进组件之后调用。
  
negative.code:     Misko Hevery，Angular项目的头，在[这里解释](http://misko.hevery.com/code-reviewers-guide/flaw-constructor-does-real-work/)了你为什么应该避免复杂的构造函数逻辑。
    
  :marked
    Don't fetch data in a component constructor.
    You shouldn't worry that a new component will try to contact a remote server when
    created under test or before you decide to display it.
  