title: Edit object with ICollection
body: <p>when I Edit a class with Virtual Icollection, the Icollection become null.
  I don't use the Icollection in the view, so I tried,hiddenfor with elementat().</p>
  
  <p>Model</p>
  
  <pre><code>public class Event
  {
      public Event() { EventId = Guid.NewGuid(); }
  
      public Guid EventId { get; set; }
  
      public string contenu { get; set; }
      public virtual ICollection&lt;BookedUser&gt; BookedUsers { get; set; }
  }
  </code></pre>
  
  <p>View</p>
  
  <pre><code>@model WebApplication2.Models.Event
  if (Model.BookedUsers.Count != null)
  {
      for (int i = 0; i &lt; Model.BookedUsers.Count(); i++)
      {
           @Html.HiddenFor(m =&gt; m.BookedUsers.ElementAt(i).BookedUserId)
  
      }
  }
  </code></pre>