Databinding collection of collections

Question

Hello

I looked for on the web during a long time and I can't find my answer.

I have two classes:

1) Customer: Customercollection which inherits from ObservableCollection.

It contains dependency property:

String Cname;
String Cemail;

OrdersCollection Orders;

2) Orders: OrdersCollection which inherits from ObservableCollection.

It contains dependency property:

Double Amount;
String Seller;

My problem: I would like to group in a listview my Customercollection with the property group CName.

 <local:MainWindow x:Key="DebutDataSource"/>
        <CollectionViewSource x:Key="ClientCollectionSelectedView" Source="{Binding Customers, Mode=Default, Source={StaticResource DebutDataSource}}">
       <CollectionViewSource.GroupDescriptions>
    <PropertyGroupDescription PropertyName="Cname"/>
  </CollectionViewSource.GroupDescriptions>

And after, I use my Listview:

<ListView Background="Black" localStretch:ListViewColumns.Stretch="true"  ItemsSource="{Binding Source={StaticResource ClientCollectionSelectedView}, Mode=Default}" IsSynchronizedWithCurrentItem="True" ItemContainerStyle="{DynamicResource ListViewItemStyle}" >
            <ListView.GroupStyle>
                <GroupStyle>
                    <GroupStyle.ContainerStyle>
                        <Style TargetType="{x:Type GroupItem}">
                            <Setter Property="Margin" Value="0,0,0,5"/>
                            <Setter Property="Template">
                                <Setter.Value>
                                    <ControlTemplate TargetType="{x:Type GroupItem}">
                                        <Expander IsExpanded="True" BorderBrush="#FFA4B97F"
                            BorderThickness="0,0,0,1">
                                            <Expander.Header>
                                                <DockPanel>
                                                    <TextBlock FontWeight="Bold" Text="{Binding Path=Name}"
                                   Margin="5,0,0,0" Width="100" Foreground="{DynamicResource TitreColor}"/>
                                                    <TextBlock FontWeight="Bold"
                                   Text="{Binding Path=ItemCount}" Foreground="{DynamicResource TitreColor}"/>
                                                </DockPanel>
                                            </Expander.Header>
                                            <Expander.Content>
                                                <ItemsPresenter />
                                            </Expander.Content>
                                        </Expander>
                                    </ControlTemplate>
                                </Setter.Value>
                            </Setter>
                        </Style>
                    </GroupStyle.ContainerStyle>
                </GroupStyle>
            </ListView.GroupStyle>
            <ListView.View>
                <GridView ColumnHeaderContainerStyle="{DynamicResource GridViewColumnHeaderStyle1}">
                    <GridViewColumn>
                    <TextBlock Text="Numéro commande" Foreground="{DynamicResource TitreColor}" FontSize="14.667" FontWeight="Bold"/>
                        <GridViewColumn.CellTemplate>
                            <DataTemplate>
                                <TextBlock Text="{Binding Path= Orders/Amount}" Foreground="{DynamicResource TitreColor}"/>
                            </DataTemplate>
                        </GridViewColumn.CellTemplate>
                    </GridViewColumn>
                </GridView>
            </ListView.View>
        </ListView>

My problem is when I have two orders for one customer, it only shows the first order. Not the second.