The following example demonstrates how to handle the PreviewMouseLeftButtonDown event on the GroupHeaderControl objects contained in the headers of the child groups to toggle the expansion state of child groups using the ToggleGroupExpansion method. The group whose state is to be toggled will be retrieved using the GetParentGroupFromItem method.

XAML

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<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid">    <Grid.Resources>      <xcdg:DataGridCollectionViewSource x:Key="cvs_orders"                                         Source="{Binding Source={x:Static Application.Current},                                                           Path=Orders}">        <xcdg:DataGridCollectionViewSource.GroupDescriptions>          <xcdg:DataGridGroupDescription PropertyName="ShipCountry"/>          <xcdg:DataGridGroupDescription PropertyName="ShipCity"/>        </xcdg:DataGridCollectionViewSource.GroupDescriptions>      </xcdg:DataGridCollectionViewSource>      <Style TargetType="{x:Type xcdg:GroupHeaderControl}">        <EventSetter Event="PreviewMouseLeftButtonDown"                     Handler="HeaderDown"/>      </Style>     </Grid.Resources>    <xcdg:DataGridControl x:Name="OrdersGrid"                          ItemsSource="{Binding Source={StaticResource cvs_orders}}"/>  </Grid>

The following code provides the implementation of the PreviewMouseLeftButtonDown event in which we will retrieve the item represented by the GroupHeaderControl (GroupHeaderFooterItem) using the GetItemFromContainer method, which will then be used to retrieve the parent group (GetParentGroupFromItem) whose state is to be toggled.

Visual Basic

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Private Sub HeaderDown( ByVal sender As Object, ByVal e As MouseEventArgs )   Dim headerControl As GroupHeaderControl = TryCast( sender, GroupHeaderControl );   If header Is Nothing Then     Return   End If   Dim context As DataGridContext = DataGridControl.GetDataGridContext( headerControl )   Dim item As Object = context.GetItemFromContainer( headerControl ) )   If Not item Is Nothing Then     Dim group As CollectionViewGroup = context.GetParentGroupFromItem( item )     If Not group Is Nothing       context.ToggleGroupExpansion( group )     End If   End If End Sub

The following code provides the implementation of the PreviewMouseLeftButtonDown event in which we will retrieve the item represented by the GroupHeaderControl (GroupHeaderFooterItem) using the GetItemFromContainer method, which will then be used to retrieve the parent group (GetParentGroupFromItem) whose state is to be toggled.

C#

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private void HeaderDown( object sender, MouseEventArgs e ) {  GroupHeaderControl headerControl = sender as GroupHeaderControl;  if( headerControl == null )    return;  DataGridContext context = DataGridControl.GetDataGridContext( headerControl );  object item = context.GetItemFromContainer( headerControl );  if( item != null )  {    CollectionViewGroup group = context.GetParentGroupFromItem( item );    if( group != null )    {      context.ToggleGroupExpansion( group );    }  } }

The following example demonstrates how to retrieve the child contexts of the master data items and collapse any expanded details using the CollapseDetail method.

XAML

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<Grid>    <Grid.Resources>       <xcdg:DataGridCollectionViewSource x:Key="cvs_employees"                                          Source="{Binding Source={x:Static Application.Current},                                                           Path=Employees}"/>       </Grid.Resources>       <DockPanel>       <Button Content="Collapse All Details"               Click="Button_Click"               DockPanel.Dock="Top"/>       <xcdg:DataGridControl x:Name="EmployeesGrid"                             ItemsSource="{Binding Source={StaticResource cvs_employees}}"                             ItemsSourceName="Order Information"                             AutoCreateDetailConfigurations="True"/>    </DockPanel>  </Grid>

The next example provides the implementation of the button's Click event.

Visual Basic

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Private Sub Button_Click( ByVal sender As Object, ByVal e As RoutedEventArgs )   DataGridContext rootContext = DataGridControl.GetDataGridContext( this.EmployeesGrid );   Dim childContexts As New List( Of DataGridContext)( Me.EmployeesGrid.GetChildContexts() )   Dim context As DataGridContext   For Each context In childContexts     context.ParentDataGridContext.CollapseDetails( context.ParentItem )   Next context End Sub

The next example provides the implementation of the button's Click event.

C#	Copy Code
private void Button_Click( object sender, RoutedEventArgs e ) { DataGridContext rootContext = DataGridControl.GetDataGridContext( this.EmployeesGrid ); List<DataGridContext> childContexts = new List<DataGridContext>( this.EmployeesGrid.GetChildContexts() ); foreach( DataGridContext context in childContexts ) {   context.ParentDataGridContext.CollapseDetails( context.ParentItem ); }      }