title: UserControl Expand Vertically when Window is expanded
body: <p>I'm having trouble getting my UserControl to expand vertically when my window is expanded.</p>
  
  <p>My UserControl currently sits inside a ItemsControl which is stretching correctly by setting the VerticalAlignment="Stretch" property on the ItemsControl.</p>
  
  <p>I add the following UserControl to the ItemsControl:</p>
  
  <pre><code>&lt;UserControl MinWidth="930"&gt;
       &lt;Grid VerticalAlignment="Stretch" Background="Red"&gt;
            &lt;Grid.ColumnDefinitions&gt;
                 &lt;ColumnDefinition Width="200" /&gt;
                 &lt;ColumnDefinition Width="730*" /&gt;
            &lt;/Grid.ColumnDefinitions&gt;
            &lt;Grid.RowDefinitions&gt;
                 &lt;RowDefinition Height="400" /&gt;
                 &lt;RowDefinition Height="*" /&gt;
            &lt;/Grid.RowDefinitions&gt;
  
            &lt;DockPanel Grid.Column="1" Grid.ColumnSpan="1" Grid.RowSpan="2" Grid.Row="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Background="Pink" LastChildFill="True"&gt;
  
                &lt;ItemsControl Name="itemPanelOverview" Grid.Column="1" Background="Black" Margin="0"/&gt;
           &lt;/DockPanel&gt;
       &lt;/Grid&gt;
  &lt;/UserControl&gt;
  </code></pre>
  
  <p>The UserControl is called in an ItemsControl inside of a TabControl like so:</p>
  
  <pre><code>&lt;TabItem&gt;
       &lt;TabItem.Header&gt;
            HEADER EG
       &lt;/TabItem.Header&gt;
  
       &lt;ItemsControl Name="contentItems" Grid.ColumnSpan="2" Grid.Column="1" Grid.Row="1" VerticalAlignment="Stretch" Background="Blue"&gt;
            &lt;Grid Height="35" Background="{DynamicResource GrayMenuGradient}" &gt;
                 &lt;Image Source="..." Stretch="None" /&gt;
                 &lt;TextBlock Text="{Binding WelcomeMessage}" /&gt;
            &lt;/Grid&gt;
      &lt;/ItemsControl&gt;
  &lt;/TabItem&gt;
  </code></pre>
  
  <p>It appears that the ItemsControl (contentItems) is stretching as expected, as I can see the blue background stretching correctly.</p>
  
  <p>I haven't set the height for this UserControl anywhere other than the Row Definitions. Is there something I'm missing?</p>