title: Ribbon ApplicationMenu AuxilaryPane Size
body: <p>How do I change the size of the AuxilaryPane in the WPF Ribbon ApplicationMenu? I have added a recent file list to that area but it is getting truncated. Ideally I'd like the auxilary pane to fill the screen like it does for Word/Excel.</p>
  
  <p>My code:</p>
  
  <pre><code>&lt;r:Ribbon.ApplicationMenu&gt;
      &lt;r:RibbonApplicationMenu&gt;
          &lt;r:RibbonApplicationMenu.AuxiliaryPaneContent&gt;
              &lt;StackPanel&gt;
                  &lt;TextBlock Text="Recent Files" /&gt;
                  &lt;Separator /&gt;
                  &lt;ItemsControl ItemsSource="{Binding RecentFiles}"&gt;
                      &lt;ItemsControl.ItemTemplate&gt;
                          &lt;DataTemplate&gt;
                              &lt;r:RibbonApplicationMenuItem Header="{Binding ShortPath}" 
                                                           Command="{Binding DataContext.OpenRecentFileCommand, RelativeSource={RelativeSource AncestorType=ItemsControl}}"
                                                           CommandParameter="{Binding LongPath}"/&gt;
                          &lt;/DataTemplate&gt;
                      &lt;/ItemsControl.ItemTemplate&gt;
                  &lt;/ItemsControl&gt;
              &lt;/StackPanel&gt;
          &lt;/r:RibbonApplicationMenu.AuxiliaryPaneContent&gt;
      &lt;/r:RibbonApplicationMenu&gt;                
  &lt;/r:Ribbon.ApplicationMenu&gt;
  </code></pre>