Xceed Toolkit Plus for WPF v5.0 Documentation
Xceed.Wpf.DataGrid Assembly / Xceed.Wpf.DataGrid Namespace / GroupConfigurationSelector Class / SelectGroupConfiguration Method
The zero-based level of the group.

The CollectionViewGroup that represents the group. Can be a null reference (Nothing in Visual Basic) if an item located in the headers or footers of a grid queries the selector for a group configuration (see Remarks).

The GroupDescription from which the group was created.
Example


    SelectGroupConfiguration Method (GroupConfigurationSelector)
    Selects the appropriate group configuration based on the specified information.
    Syntax
    'Declaration
     
    Public Overridable Function SelectGroupConfiguration( _
       ByVal groupLevel As Integer, _
       ByVal collectionViewGroup As CollectionViewGroup, _
       ByVal groupDescription As GroupDescription _
    ) As GroupConfiguration
     
    'Usage
     
    Dim instance As GroupConfigurationSelector
    Dim groupLevel As Integer
    Dim collectionViewGroup As CollectionViewGroup
    Dim groupDescription As GroupDescription
    Dim value As GroupConfiguration
     
    value = instance.SelectGroupConfiguration(groupLevel, collectionViewGroup, groupDescription)

    Parameters

    groupLevel
    The zero-based level of the group.
    collectionViewGroup

    The CollectionViewGroup that represents the group. Can be a null reference (Nothing in Visual Basic) if an item located in the headers or footers of a grid queries the selector for a group configuration (see Remarks).

    groupDescription
    The GroupDescription from which the group was created.

    Return Value

    The GroupConfiguration that will be applied to the group. Can be a null reference (Nothing in Visual Basic) if the selector does not have a group configuration that corresponds to the specified information.
    Remarks

    When a grid is in a table-view layout, rows located in the headers, footers, fixed headers, and fixed footers of a grid (e.g., ColumnManagerRows, InsertionRows) will query the selector in order to retrieve the GroupLevelIndicatorStyle of the appropriate group configuration. In this case, collectionViewGroup will be a null reference (Nothing in Visual Basic). If the selector chooses group configurations based on the specified collectionViewGroup, a "dummy" group configuration that provides an identical group-level-indicator style should be returned. For example, if a group configuration sets the width of its group-level indicator to 30, the "dummy" group configuration should also return 30 in its group-level-indicator style so that the items in the headers and footers have the same indentation as the other items to preserve cell alignment.

    It is recommended that all group-level-indicator styles return the same width to preserve the alignment of the cells throught the grid.

    Example
    All examples in this topic assume that the grid is bound to the Orders table of the Northwind database, unless stated otherwise.
    The following example demonstrates how to create a custom group-configuration selector that will return the appropriate group configuration depending on the number of items in a group. The implementation of the ItemCountGroupConfigurationSelector is provided below.
    <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="ShipCity" />
          </xcdg:DataGridCollectionViewSource.GroupDescriptions>
        </xcdg:DataGridCollectionViewSource>
      </Grid.Resources>
      <xcdg:DataGridControl x:Name="OrdersGrid"
                            ItemsSource="{Binding Source={StaticResource cvs_orders}}">
    
        <xcdg:DataGridControl.GroupConfigurationSelector>
          <local:ItemCountGroupConfigurationSelector MinItemCount="10" />
        </xcdg:DataGridControl.GroupConfigurationSelector>
      </xcdg:DataGridControl>
    </Grid>
    The following code provides the implementation of the ItemCountGroupConfigurationSelector.
    Public Class ItemCountGroupConfigurationSelector
                   Inherits GroupConfigurationSelector
        Public Sub New
        End Sub
        Public Overrides Function SelectGroupConfiguration( ByVal groupLevel As Integer, _
                        ByVal collectionViewGroup As System.Windows.Data.CollectionViewGroup, _
                        ByVal groupDescription As System.ComponentModel.GroupDescription ) As GroupConfiguration
    
          If collectionViewGroup Is Nothing Then
            Return MyBase.SelectGroupConfiguration( groupLevel, collectionViewGroup, groupDescription )
          End If
          Dim groupConfiguration As New GroupConfiguration()
          Dim style As New Style( GetType( Xceed.Wpf.DataGrid.DataRow ) )
    
          If collectionViewGroup.ItemCount <= m_minItemCount Then ' red
            style.Setters.Add( New Setter( DataRow.BackgroundProperty, Brushes.Red ) )
          Else ' green
            style.Setters.Add( New Setter( DataRow.BackgroundProperty, Brushes.LightGreen ) )
          End If
          groupConfiguration.ItemContainerStyle = style
          Return groupConfiguration
        End Function
        Private m_minItemCount As Integer = 0
        Public Property MinItemCount As Integer
          Get
            Return m_minItemCount
          End Get
          Set
            m_minItemCount = value
        End Property
      End Class
    The following code provides the implementation of the ItemCountGroupConfigurationSelector.
    public class ItemCountGroupConfigurationSelector : GroupConfigurationSelector
      {
        public ItemCountGroupConfigurationSelector()
        {
        } 
       public override GroupConfiguration SelectGroupConfiguration( int groupLevel,
                       System.Windows.Data.CollectionViewGroup collectionViewGroup,
                       System.ComponentModel.GroupDescription groupDescription )
       {
         if( collectionViewGroup == null )
           return base.SelectGroupConfiguration( groupLevel, collectionViewGroup, groupDescription );
         GroupConfiguration groupConfiguration = new GroupConfiguration();
         Style style = new Style( typeof( Xceed.Wpf.DataGrid.DataRow ) );
    
         if( collectionViewGroup.ItemCount <= m_minItemCount ) // red
         {
           style.Setters.Add( new Setter( DataRow.BackgroundProperty, Brushes.Red ) );       
         }
         else // green
         {
           style.Setters.Add( new Setter( DataRow.BackgroundProperty, Brushes.LightGreen ) );       
         }
         groupConfiguration.ItemContainerStyle = style;
         return groupConfiguration;
       }
        private int m_minItemCount = 0;
        public int MinItemCount
        {
          get
          {
            return m_minItemCount;
          }
          set
          {
            if( value != m_minItemCount )
              m_minItemCount = value;
          }
        }
      }
    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