title: What's the purpose of having a ViewContext property on a Tag Helper?
body: <p>I have 2 questions: <br>
  <br>
   1. what is Viewcontext and what are its advantages?<br>
   2. why we have to use it in tag helpers?</p>
  
  <p>Actually i am the beginner and follow the "Pro ASP.NET Core MVC,6th Edition"  by adam freeman in this he make a taghelper class in which he uses </p>
  
  <pre><code> [ViewContext]
   [HtmlAttributeNotBound]
   public ViewContext ViewContext { get; set; }
  </code></pre>
  
  <p>He didn't explain the above piece of code why he uses these properties in square brackets purpose of these properties.
  And please share a link which describe about these type of properties if any  </p>