title: Fill DockPanel middle area by a grid
body: <p>I have below XAML, I want to make the middle Grid (the green one) to fill all the area between the top Blue and the bottom Red grids. Please help me to set it up</p>
  
  <pre><code>&lt;Window x:Class="WpfApplication1.Window1"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="Window1" SizeToContent="WidthAndHeight"&gt;
  &lt;DockPanel MinWidth="600" Background="Gold"&gt;
      &lt;Grid DockPanel.Dock="Top" Background="Blue" Height="30"&gt;&lt;/Grid&gt;
      &lt;Grid DockPanel.Dock="Top" Background="Chartreuse" MinHeight="100" VerticalAlignment="Stretch"&gt;&lt;/Grid&gt;
      &lt;Grid DockPanel.Dock="Bottom" Background="Red" Height="10" VerticalAlignment="Bottom"&gt;&lt;/Grid&gt;
  &lt;/DockPanel&gt;
  </code></pre>
  
  <p></p>