title: GroupBox Header Not Showing
body: <p>I followed an this <a href="https://stackoverflow.com/questions/3883955/wpf-itemscontrol-itemtemplate-border-with-groupstyle">StackOverflow</a> question, which has a link to another article, on how to group data, but my header is not showing. Can someone point me to the problem of why my header is not showing in the grouping of my data. The only thing different between the article and my markup that I see is that my data is in a different format, but I have no control on how I receive it.</p>
  
  <p>Representation of my data:</p>
  
  <pre><code>&lt;MyDetails xmlns="clr-namespace:MyCompany.Mapping;assembly=Mapping" xmlns:scg="clr-
      namespace:System.Collections.Generic;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"&gt;
      &lt;MyDetails.Details&gt;
          &lt;scg:List x:TypeArguments="MyAttributes" Capacity="64"&gt;
              &lt;MyAttributes Bit="0" Channel="1" Name="SomeName" IOAttribute="O" /&gt;
          &lt;/scg:List&gt;
      &lt;/MyDetails.Details&gt;
  &lt;/MyDetails&gt;
  </code></pre>
  
  <p>ViewModel Property I bind to:</p>
  
  <pre><code>ObservableCollection&lt;MyDetails&gt; Channels= new 
  ObservableCollection&lt;MyDetails&gt;();
  </code></pre>
  
  <p>MyDetails Class Public Property (Defined as a DataMember):</p>
  
  <pre><code>List&lt;MyAttributes&gt; Details = new List&lt;MyAttributes&gt;();
  </code></pre>
  
  <p>MyAttributes Class Public Properties (All defined as a DataMembers):</p>
  
  <pre><code>property string Channel {get; set;}
  property string Bit {get; set;}
  property string Name {get; set;}
  property string Attribute {get; set;}
  </code></pre>
  
  <p>XAML Resource Header:</p>
  
  <pre><code>&lt;CollectionViewSource x:Key="MyDetails" Source="{Binding Channels[0].Details}"&gt;
      &lt;CollectionViewSource.GroupDescriptions&gt;
          &lt;PropertyGroupDescription PropertyName="Channel" /&gt;
      &lt;/CollectionViewSource.GroupDescriptions&gt;
  &lt;/CollectionViewSource&gt;
  </code></pre>
  
  <p>XAML:</p>
  
  <pre><code>&lt;ItemsControl ItemsSource="{Binding Source={StaticResource MyDetails}}"&gt;
  &lt;ItemsControl.GroupStyle&gt;
      &lt;GroupStyle&gt;
          &lt;GroupStyle.ContainerStyle&gt;
              &lt;Style TargetType="{x:Type GroupItem}"&gt;
                  &lt;Setter Property="Template"&gt;
                      &lt;Setter.Value&gt;
                          &lt;ControlTemplate TargetType="{x:Type GroupItem}"&gt;
                              &lt;GroupBox Margin="10" &gt;
                                  &lt;GroupBox.Header&gt;
                                  &lt;TextBlock Text="{Binding Channel}" FontWeight="Bold" FontSize="16" /&gt; &lt;!-- Does not show --&gt;
                                  &lt;/GroupBox.Header&gt;
                                  &lt;ItemsPresenter /&gt;
                              &lt;/GroupBox&gt;
                          &lt;/ControlTemplate&gt;
                      &lt;/Setter.Value&gt;
                  &lt;/Setter&gt;
              &lt;/Style&gt;
          &lt;/GroupStyle.ContainerStyle&gt;
      &lt;/GroupStyle&gt;
  &lt;/ItemsControl.GroupStyle&gt;
  &lt;ItemsControl.ItemTemplate&gt;
      &lt;DataTemplate&gt;
          &lt;StackPanel Orientation="Horizontal"&gt;
              &lt;TextBlock Text="{Binding Path=Bit}" Width="50" /&gt;
              &lt;TextBlock Text="{Binding Path=Name}" Width="150" /&gt;
              &lt;TextBlock Text="{Binding Path=Attribute}" Width="50" /&gt;
          &lt;/StackPanel&gt;
      &lt;/DataTemplate&gt;
  &lt;/ItemsControl.ItemTemplate&gt;
  &lt;/ItemsControl&gt;
  </code></pre>