title: How to add a string.Empty choice in a dropdownFor model in MVC 5
body: <p>I have a drop-down which display a list of items from database, like this:</p>
  
  <pre><code>&lt;div class="form-group"&gt;
              @Html.LabelFor(model =&gt; model.ParentID, "ParentID")
              &lt;div class="col-md-10"&gt;
                  @Html.DropDownList("ParentID", null,"Select Item")
                  @Html.ValidationMessageFor(model =&gt; model.ParentID, "")
              &lt;/div&gt;
          &lt;/div&gt;
  </code></pre>
  
  <p>I use ViewBag to transfer the list, and this is scaffold-it code (I delete the html object). </p>
  
  <p>My model accept null values for this property, but I am not able to give it. </p>
  
  <p>I need a way to insert a null option in the list, or to keep permanent the "Select Item". 
  My problem exist only in the cases when I want to edit the object and select a null value for this property. This is not possible, because I do not have null value in list. </p>
  
  <p>There is any possibility to insert a null option using drop-down properties? </p>