How can I create a group footer in a WPF ListView ( GridView )

If your looking for something like this:

_{(source: bendewey.com)}

Then you can use the Template property of the ContainerStyle for the GroupStyle. In this example I use a DockPanel, with the Grid you supplied Docked on the bottom and an ItemsPresenter filling the remainder. In addition in order to get the Items totaled you'd have to use a Converter, which is supplied at the bottom.

Window.xaml

<Window    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    x:Class="WpfApplication1.Window3"    x:Name="Window"    Title="Window3"    xmlns:local="clr-namespace:WpfApplication1"    Width="640" Height="480">    <Window.Resources>        <local:MyDataSource x:Key="MyData" />        <CollectionViewSource x:Key="ViewSource" Source="{Binding Source={StaticResource MyData}, Path=Users}">            <CollectionViewSource.GroupDescriptions>                <PropertyGroupDescription PropertyName="Country" />            </CollectionViewSource.GroupDescriptions>        </CollectionViewSource>    </Window.Resources>    <Grid x:Name="LayoutRoot">      <ListView ItemsSource="{Binding Source={StaticResource ViewSource}}">        <ListView.GroupStyle>            <GroupStyle>                <GroupStyle.ContainerStyle>                    <Style TargetType="{x:Type GroupItem}">                        <Setter Property="Template">                            <Setter.Value>                                <ControlTemplate TargetType="{x:Type GroupItem}">                                      <DockPanel>                                        <Grid DockPanel.Dock="Bottom">                                            <Grid.Resources>                                                <local:TotalSumConverter x:Key="sumConverter" />                                            </Grid.Resources>                                            <Grid.ColumnDefinitions>                                                <ColumnDefinition Width="*" />                                                <ColumnDefinition Width="*" />                                            </Grid.ColumnDefinitions>                                            <Grid.RowDefinitions>                                                <RowDefinition />                                                <RowDefinition />                                            </Grid.RowDefinitions>                                            <StackPanel Orientation="Horizontal">                                                <TextBlock Grid.Column="0" Text="Total: " FontWeight="Bold"/>                                                <TextBlock Grid.Column="0" Text="{Binding Path=Name}" />                                            </StackPanel>                                            <Line Grid.Column="1" Stroke="Black" X2="500" Fill="Black" VerticalAlignment="Center" />                                            <TextBlock Grid.Row="1" Grid.Column="1" HorizontalAlignment="Right" Text="{Binding Path=Items, Converter={StaticResource sumConverter}}" />                                        </Grid>                                    <ItemsPresenter />                                </DockPanel>                                </ControlTemplate>                            </Setter.Value>                        </Setter>                    </Style>                </GroupStyle.ContainerStyle>            </GroupStyle>        </ListView.GroupStyle>        <ListView.View>           <GridView>            <GridViewColumn Width="140" Header="Name" DisplayMemberBinding="{Binding Name}"/>            <GridViewColumn Width="140" Header="Phone Number" DisplayMemberBinding="{Binding Phone}"/>            <GridViewColumn Width="140" Header="Country" DisplayMemberBinding="{Binding Country}" />            <GridViewColumn Width="140" Header="Total" DisplayMemberBinding="{Binding Total}" />           </GridView>          </ListView.View>      </ListView>    </Grid></Window>

MyDataSource.cs

public class MyDataSource{    public ObservableCollection<User> Users { get; set; }    public MyDataSource()    {        Users = new ObservableCollection<User>();        LoadDummyData();    }    private void LoadDummyData()    {        Users.Add(new User()        {            Name = "Frank",            Phone = "(122) 555-1234",            Country = "USA",            Total = 432        });        Users.Add(new User()        {            Name = "Bob",            Phone = "(212) 555-1234",            Country = "USA",            Total = 456        });        Users.Add(new User()        {            Name = "Mark",            Phone = "(301) 555-1234",            Country = "USA",            Total = 123        });        Users.Add(new User()        {            Name = "Pierre",            Phone = "+33 (122) 555-1234",            Country = "France",            Total = 333        });        Users.Add(new User()        {            Name = "Jacques",            Phone = "+33 (122) 555-1234",            Country = "France",            Total = 222        });        Users.Add(new User()        {            Name = "Olivier",            Phone = "+33 (122) 555-1234",            Country = "France",            Total = 444        });    }}

User.cs

public class User{    public string Name { get; set; }    public string Phone { get; set; }    public string Country { get; set; }    public double Total { get; set; }}

TotalSumConverter.cs

public class TotalSumConverter : IValueConverter{    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)    {        var users = value as IEnumerable<object>;        if (users == null)            return "$0.00";        double sum = 0;        foreach (var u in users)        {            sum += ((User)u).Total;        }        return sum.ToString("c");    }    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)    {        throw new System.NotImplementedException();    }}