Example 3 clearly demonstrates how to use the StatContext attached property. Here is the example (I will fix the documentation)
<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid">
<Grid.Resources>
<xcdg:DataGridCollectionViewSource x:Key="cvs_orderdetails"
Source="{Binding Source={x:Static Application.Current},
Path=OrderDetails}">
<xcdg:DataGridCollectionViewSource.StatFunctions>
<xcdg:CountFunction ResultPropertyName="orderid_count"
SourcePropertyName="OrderID"/>
<xcdg:SumFunction ResultPropertyName="unitprice_sum"
SourcePropertyName="UnitPrice"/>
<xcdg:AverageFunction ResultPropertyName="unitprice_average"
SourcePropertyName="UnitPrice"/>
<xcdg:SumFunction ResultPropertyName="quantity_sum"
SourcePropertyName="Quantity"/>
</xcdg:DataGridCollectionViewSource.StatFunctions>
<xcdg:DataGridCollectionViewSource.GroupDescriptions>
<xcdg:DataGridGroupDescription PropertyName="ProductID"/>
</xcdg:DataGridCollectionViewSource.GroupDescriptions>
</xcdg:DataGridCollectionViewSource>
<xcdg:StatResultConverter x:Key="valueConverter"/>
</Grid.Resources>
<xcdg:DataGridControl x:Name="OrderDetailsGrid"
ItemsSource="{Binding Source={StaticResource cvs_orderdetails}}">
<xcdg:DataGridControl.DefaultGroupConfiguration>
<xcdg:GroupConfiguration>
<xcdg:GroupConfiguration.Footers>
<xcdg:GroupHeaderFooterItemTemplate VisibleWhenCollapsed="True">
<DataTemplate>
<Border Background="#999999"
BorderBrush="LightBlue"
BorderThickness="3"
Margin="5" >
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Text="Total Orders: " Grid.Row="0" Grid.Column="0"/>
<TextBlock Text="{Binding RelativeSource={RelativeSource Self},
Path=(xcdg:DataGridControl.StatContext).orderid_count}"
Grid.Row="0" Grid.Column="1"/>
<TextBlock Text="Total Quantity Sold: " Grid.Row="1" Grid.Column="0"/>
<TextBlock Text="{Binding RelativeSource={RelativeSource Self},
Path=(xcdg:DataGridControl.StatContext).quantity_sum}"
Grid.Row="1" Grid.Column="1"/>
<TextBlock Text="Total Sales: " Grid.Row="2" Grid.Column="0"/>
<TextBlock Text="{Binding RelativeSource={RelativeSource Self},
Path=(xcdg:DataGridControl.StatContext).unitprice_sum}"
Grid.Row="2" Grid.Column="1"/>
<TextBlock Text="Average Unit Price: " Grid.Row="3" Grid.Column="0"/>
<TextBlock Text="{Binding RelativeSource={RelativeSource Self},
Path=(xcdg:DataGridControl.StatContext).unitprice_average,
Converter={StaticResource valueConverter},
ConverterParameter=f2}"
Grid.Row="3" Grid.Column="1"/>
</Grid>
</Border>
</DataTemplate>
</xcdg:GroupHeaderFooterItemTemplate>
</xcdg:GroupConfiguration.Footers>
</xcdg:GroupConfiguration>
</xcdg:DataGridControl.DefaultGroupConfiguration>
</xcdg:DataGridControl>
</Grid>
Technical Writer - Xceed Software
Of all the things I've lost, I miss my mind the most. - Mark Twain