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.
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.
publicclass ItemCountGroupConfigurationSelector : GroupConfigurationSelector
{
public ItemCountGroupConfigurationSelector()
{
}
publicoverride GroupConfiguration SelectGroupConfiguration( int groupLevel,
System.Windows.Data.CollectionViewGroup collectionViewGroup,
System.ComponentModel.GroupDescription groupDescription )
{
if( collectionViewGroup == null )
returnbase.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;
}
privateint m_minItemCount = 0;
publicint 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