title: MVC 3 Html.DropDownList error
body: <p>I have that error </p>
  
  <pre><code>The ViewData item that has the key 'BookAttributesDDL' is of type 'System.String' but must be of type 'IEnumerable&lt;SelectListItem&gt;'.
  </code></pre>
  
  <p>in that code:</p>
  
  <pre><code>@Html.DropDownList("BookAttributesDDL", Model.BookAttributes_Items)
  </code></pre>
  
  <p>but the <code>Model.BookAttributes_Items</code> is type of the <code>IEnumerable&lt;SelectListItem&gt;</code> ! What's wrong ?</p>
  
  <p>The <code>ViewData.Keys</code> property from the Immediate Window:</p>
  
  <pre><code>ViewData.Keys
  Count = 2
      [0]: "FCoookie"
      [1]: "Title"
  </code></pre>