title: Custom attributes in C#
body: <p>I have a custom attribute for my page like this:</p>
  
  <pre><code>[PageDefinition("My page", "~/Parts/MyPage.aspx")]
  </code></pre>
  
  <p>My PageDefinition looks like this, where AttributeItemDefinitions is get set for Title, Url, IsPage and IsUserControl</p>
  
  <pre><code>public class PageDefinition : AttributeItemDefinitions
  {
      public PageDefinition(string title, string url)
          : this()
      {
          Title = title;
          Url = Url;
      }
  
      public PageDefinition()
      {
          IsPage = true;
          IsUserControl = false;
      }
  }
  </code></pre>
  
  <p>But i can't find any good way to add all page with that attribute to a placeholder where all  links should be list with the title and url. Do you have any good idea? Thanks for your help.</p>