title: Mahapp SplitButton not working correctly
body: <p>In the Mahapp's documentation, <code>SplitButton</code> used <code>binding</code> to get its datasource. But I just want to add <code>SplitButton</code>'s data manually.</p>
  
  <pre><code>&lt;controls:SplitButton Grid.Row="3"
      HorizontalContentAlignment="Left"
      HorizontalAlignment="Center"
      VerticalContentAlignment="Center"
      Width="120"
      DisplayMemberPath="Title"
      VerticalAlignment="Top"&gt;
              &lt;controls:SplitButton.Items&gt;
                  &lt;Label&gt;1&lt;/Label&gt;
                  &lt;Label&gt;2&lt;/Label&gt;
              &lt;/controls:SplitButton.Items&gt;
  &lt;/controls:SplitButton&gt;
  </code></pre>
  
  <p>However, I'm not able to see the popup window. Any ideas?</p>
  
  <p><img src="https://i.stack.imgur.com/nGmV0.png" alt="enter image description here"></p>