title: GetEnumSelectList generates an empty combo box in RazorPages
body: <p>I started on a new project with ASP.NET Core and ran into the following problem:</p>
  
  <p>When I try to populate a select list from an enum, I just get an empty combo box... I am using .NET Core 2.0 with Razor Pages.</p>
  
  <p>I have reconstructed the code I have on my actual project with the bare bones of the part that I want to get to work.</p>
  
  <p>The enum:</p>
  
  <pre><code>    namespace EnumTest2
  {
      public enum SomeEnum
      {
          Test1,
          Test2,
          Test3
      }
  }
  </code></pre>
  
  <p>The class:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.ComponentModel.DataAnnotations;
  using System.Linq;
  using System.Threading.Tasks;
  
  namespace EnumTest2
  {
      public class SomeClass
      {
          [Required]
          public SomeEnum TheEnum { get; set; }
      }
  }
  </code></pre>
  
  <p>The Page Model:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.Linq;
  using System.Threading.Tasks;
  using Microsoft.AspNetCore.Mvc;
  using Microsoft.AspNetCore.Mvc.RazorPages;
  
  namespace EnumTest2.Pages
  {
      public class IndexModel : PageModel
      {
          [BindProperty]
          public SomeClass TheClass { get; set; }
  
          public void OnGet()
          {
  
          }
  
          public void OnPost()
          {
  
          }
      }
  }
  </code></pre>
  
  <p>The View:</p>
  
  <pre><code>@page
  @using EnumTest2
  @model EnumTest2.Pages.IndexModel
  @addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
  
  &lt;h2&gt;Index&lt;/h2&gt;
  
  &lt;form method="post"&gt;
      &lt;select asp-for="TheClass.TheEnum" asp-items="Html.GetEnumSelectList&lt;SomeEnum&gt;()" /&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>The HTML generated:</p>
  
  <pre><code>&lt;h2&gt;Index&lt;/h2&gt;
  
  &lt;form method="post"&gt;
      &lt;select data-val="true" data-val-required="The TheEnum field is required." id="TheClass_TheEnum" name="TheClass.TheEnum" /&gt;
  &lt;input name="__RequestVerificationToken" type="hidden" value="CfDJ8KHMPQ1QRaBJumCjTcSE3GQtDZZLAoWv1Pcob_bJ71FI-ccIP1AnWuJ2WHdjF6qfWZdPTDNd9RybY0NvzXQ-uMslDfltFcGdUfYDOTzK8KB8qTodZ2BO3rx1c3WqiF_W2pKyrI30QdWzJW1Lvuq5-bI" /&gt;&lt;/form&gt;
  </code></pre>
  
  <p>According to tutorials and answers on SO I have found so far, this is the correct way of doing things and it should generate the enum values as options for the select, but as you can see it generates an empty select tag.</p>