title: Align label to the middle of dock panel
body: <p>I have a dock panel, with one label in the middle and another button on the far right.</p>
  
  <p>Because of the button the label cannot align to the middle when the windows is maximized.</p>
  
  <p>WPF:</p>
  
  <pre><code>&lt;DockPanel Height="40" HorizontalAlignment="Stretch" Margin="-1,-2,0,0" Name="dockPanel1" VerticalAlignment="Stretch" Width="Auto" OpacityMask="{x:Null}"&gt;
              &lt;Label FontSize="18" Content="Sales" FontWeight="Bold" FontFamily="Arial" Width="883" Height="42" HorizontalAlignment="Center" HorizontalContentAlignment="Center" Foreground="White" DockPanel.Dock="Left" VerticalAlignment="Center" VerticalContentAlignment="Center"&gt;&lt;/Label&gt;
              &lt;Button FontSize="18" Height="47" Width="123" Name="btnStart" Foreground="White" BorderBrush="{x:Null}" FlowDirection="LeftToRight" HorizontalContentAlignment="Center" FontFamily="Arial Rounded MT" ClickMode="Press" DockPanel.Dock="Right" HorizontalAlignment="Right" VerticalAlignment="Center" Padding="0" Content="Start" BorderThickness="0" Focusable="False"&gt;
          &lt;/DockPanel&gt;
  </code></pre>