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Xceed DataGrid for WPF v7.3 Documentation
Xceed.Wpf.DataGrid Assembly / Xceed.Wpf.DataGrid Namespace / DataGridContext Class / GetParentGroupFromItem Method
The item whose parent group is to be retrieved.
Example


In This Topic
    GetParentGroupFromItem Method (DataGridContext)
    In This Topic
    Retrieves the parent group for the specified item.
    Syntax
    'Declaration
 
Public Function GetParentGroupFromItem( _
   ByVal item As Object _
) As CollectionViewGroup
    'Usage
 
Dim instance As DataGridContext
Dim item As Object
Dim value As CollectionViewGroup
 
value = instance.GetParentGroupFromItem(item)
    public CollectionViewGroup GetParentGroupFromItem( 
   object item
)

    Parameters

    item
    The item whose parent group is to be retrieved.

    Return Value

    A CollectionViewGroup representing the parent group of the specified item. Can be a null reference (Nothing in Visual Basic) if the item is part of the context but does not have parent group.
    Example
    All examples in this topic assume that the grid is bound to the Orders or Employees table of the Northwind database, unless stated otherwise.
    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.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.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.The following example demonstrates how to retrieve the parent group of the current item using the GetParentGroupFromItem method so that it can be collapsed. The implementation for the CollapseCurrentGroup method is provided below.The following provides the implementation for the CollapseCurrentGroup method.The following provides the implementation for the CollapseCurrentGroup method.
    <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>
    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
    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 );
    }
  }
}
    <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>
  </Grid.Resources>
  <DockPanel>

    <Button Content="Collapse Group"
             Click="CollapseCurrentGroup"
            DockPanel.Dock="Top"/>
    <xcdg:DataGridControl x:Name="OrdersGrid"
                          ItemsSource="{Binding Source={StaticResource cvs_orders}}"
                          DockPanel.Dock="Bottom"/>
  </DockPanel>
</Grid>
    Private Sub CollapseCurrentGroup( ByVal sender As Object, ByVal e As RoutedEventArgs )

  Dim context As DataGridContext = Me.OrdersGrid.CurrentContext

  Dim group As CollectionViewGroup = context.GetParentGroupFromItem( context.CurrentItem )
  context.CollapseGroup( group )
End Sub
    private void CollapseCurrentGroup( object sender, RoutedEventArgs e )
{

  DataGridContext context = this.OrdersGrid.CurrentContext;
  CollectionViewGroup group = context.GetParentGroupFromItem( context.CurrentItem );
  context.CollapseGroup( group );
}
    Requirements

    Target Platforms: Windows 11, Windows, 10, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

    See Also

    Reference

    DataGridContext Class
    DataGridContext Members

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