WPF DataGrid GroupStyle

Question

I have the following DataGrid in WPF with two groups.
First group is a bool flag which represents if a person is active/inactive.
The second group (or sub-g

Answer 1

I would highly recommend changing the data structure to:

public class Person {
    public bool Active { get; set; }
    public int ID { get; set; }
    public string Name { get; set; }

    public Collection Cities { get; set; }
}

Otherwise you can change this GroupStyle

<GroupStyle>
    <GroupStyle.HeaderTemplate>
        <DataTemplate>
            <StackPanel Orientation="Horizontal" Background="LightSteelBlue">
                <TextBlock Text="{Binding Name}" Foreground="White" Margin="5 2 5 2"/>
            </StackPanel>
        </DataTemplate>
    </GroupStyle.HeaderTemplate>
</GroupStyle>

To

<GroupStyle>
    <GroupStyle.ContainerStyle>
        <Style TargetType="{x:Type GroupItem}">
            <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type GroupItem}">
                <Grid>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition SharedSizeGroup="EditButtonColumn" />
                        <ColumnDefinition SharedSizeGroup="IDColumn"  />
                        <ColumnDefinition SharedSizeGroup="NameColumn" />
                        <ColumnDefinition SharedSizeGroup="PresenterColumn" Width="*" />
                    </Grid.ColumnDefinitions>
                    <Button Grid.Column="0" BorderThickness="0" Content="Edit" Margin="3"
                CommandParameter="{Binding Path=Items[0]}" />
                    <TextBlock Grid.Column="1" Text="{Binding Path=Items[0].ID}" />
                    <TextBlock Grid.Column="2" Text="{Binding Path=Items[0].Name}" />

                    <ItemsPresenter Grid.Column="3" />
                </Grid>
                </ControlTemplate>
            </Setter.Value>
            </Setter>
        </Style>
    </GroupStyle.ContainerStyle>
</GroupStyle>

Change the template to suit your needs