title: Why controller no works only in Html.PartialAsync?
body: <p>Now I have a controller:</p>
  <pre><code>public async Task&lt;IActionResult&gt; Location()
          {
              Models.LocationModel Location = null;
              //some logic
              return View(Location);
          }
  </code></pre>
  <p>And here is the View:</p>
  <pre><code>@model Vishdo.Models.LocationModel
  &lt;div&gt;
      &lt;h5&gt;@Model.City&lt;/h5&gt;
      &lt;span&gt;@Model.Name&lt;/span&gt;
      &lt;span&gt;@Model.Phone&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  <p>When I access the View by the URL(https://localhost:44372/home/location) directly, all works well.</p>
  <p>Now I add it into the <code>_Layout.cshtml</code> like this:</p>
  <pre><code>@Html.PartialAsync(&quot;/Views/Home/Location.cshtml&quot;)
  </code></pre>
  <p>After it ran, it reports an error on the View <code>Location.cshtml</code>:</p>
  <pre><code>System.NullReferenceException
    HResult=0x80004003
    Message=Object reference not set to an instance of an object.
    Source=Sample.Views
    StackTrace:
     at AspNetCore.Views_Home_Location.&lt;ExecuteAsync&gt;d__0.MoveNext() in E:\Project\Sample\Views\Home\Location.cshtml:line 3
  </code></pre>
  <p>I added a breakpoint in the Location controller and found it never works. So the Model always is null and reports this error.</p>
  <p>In addition, I add this into the <code>_Layout.cshtml</code> for this feature is needed by all the pages and the <code>_Layout.cshml</code> has not a controller so I have to do it like this.</p>
  <p>What's wrong with my code? How can I solve it? Thank you.</p>