title: WPF Ribbon combobox select default item
body: <p>How do I select, for example, the first value <code>Select</code> to appear by default as selected item when control is displaied. Currently does not appear nothing.</p>
  
  <pre><code> &lt;RibbonComboBox Width="50" Margin="0,0,0,2" DisplayMemberPath="Select"&gt; 
                  &lt;RibbonGallery SelectedValue="Select"&gt;
                      &lt;RibbonGalleryCategory &gt;
                          &lt;RibbonGalleryItem Content="Select" /&gt;
                          &lt;RibbonGalleryItem Content="Expand" /&gt;
                          &lt;RibbonGalleryItem Content="Collapse" /&gt;
                      &lt;/RibbonGalleryCategory&gt;
                  &lt;/RibbonGallery&gt;
              &lt;/RibbonComboBox&gt;
  </code></pre>