Expander Control Sample

Inheritance of System.Windows.Controls.Expander :

System.Object
 System.Windows.Threading.DispatcherObject
  System.Windows.DependencyObject
   System.Windows.Media.Visual
    System.Windows.UIElement
     System.Windows.FrameworkElement
      System.Windows.Controls.Control
       System.Windows.Controls.ContentControl
        System.Windows.Controls.HeaderedContentControl
         System.Windows.Controls.Expander

An Expander wraps a region of content that the user can show or hide by clicking a small arrow. It is used frequently in online help and on web pages to allow them to include large amounts of temporal content. The image shows a Grid of 4 collapsed Expanders with 4 ExpandDirections. When an Expander is collapsed, its arrow points in the direction where it will expand.

<Page xmlns  ="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      Width="300">
 <Page.Resources>
  <Style TargetType="{x:Type TextBlock}">
   <Setter Property="TextWrapping" Value="Wrap"/>
   <Setter Property="Text" Value=
       "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
        Nam mi sapien, viverra et, lacinia varius, ullamcorper sed, sapien."/>
  </Style>
  <Style TargetType="{x:Type Expander}">
   <Setter Property="Margin" Value="5"/>
   <Setter Property="Padding" Value="5"/>
   <Setter Property="BorderThickness" Value="1"/>
   <Setter Property="BorderBrush" Value="Black"/>
   <Setter Property="Margin" Value="5"/>   
  </Style> 
 </Page.Resources>
 <Grid>
  <Grid.RowDefinitions>
   <RowDefinition Height="Auto"></RowDefinition>
   <RowDefinition Height="Auto"></RowDefinition>
  </Grid.RowDefinitions>
  <Grid.ColumnDefinitions>
   <ColumnDefinition></ColumnDefinition>
   <ColumnDefinition></ColumnDefinition>
  </Grid.ColumnDefinitions>
  <Expander Header="E 1">
   <TextBlock/>
  </Expander>
  <Expander Header="E 2" Grid.Column="1"              ExpandDirection="Right">
   <TextBlock/>
  </Expander>
  <Expander Header="E 3" Grid.Row="1"                 ExpandDirection="Up">
   <TextBlock/>
  </Expander>
  <Expander Header="E 4" Grid.Row="1" Grid.Column="1" ExpandDirection="Left">
   <TextBlock/>
  </Expander>
 </Grid>
</Page>

When you are in the Internet Explorer run Expander.xaml and click its items !