WinRT ControlTemplate ItemsPanel

Question

I'm new to WinRT and am trying to create a standard gridview which has a group heading with a number of tiles beneath it. That bit is easy. I'm trying to modify it so that beneath the grid of tiles I can also add a footer using the containers style:

    <GridView
        x:Name="itemGridView"
        AutomationProperties.AutomationId="ItemGridView"
        AutomationProperties.Name="Grouped Items"
        Margin="116,0,40,46"
        ItemsSource="{Binding Source={StaticResource groupedItemsViewSource}}"
        ItemTemplate="{StaticResource Project200x200ItemTemplate}"                
        SelectionMode="None"
        IsItemClickEnabled="True"
        ItemClick="ItemView_ItemClick">

        <GridView.ItemsPanel>
            <ItemsPanelTemplate>
                <VirtualizingStackPanel Orientation="Horizontal"/>
            </ItemsPanelTemplate>
        </GridView.ItemsPanel>

        <GridView.GroupStyle>
            <GroupStyle>
                <GroupStyle.HeaderTemplate>
                    <DataTemplate>
                        <Grid Margin="1,0,0,6">
                            <Button
                                AutomationProperties.Name="Group Title"
                                Content="{Binding Name}"
                                Click="Header_Click"
                                Style="{StaticResource TextButtonStyle}" 
                                FontWeight="{Binding IsSelected, ConverterParameter=FontWeight, Converter={StaticResource BooleanToFontWeightConverter}}"
                               />
                        </Grid>
                    </DataTemplate>
                </GroupStyle.HeaderTemplate>
                <GroupStyle.Panel>                           
                    <ItemsPanelTemplate>
                        <VariableSizedWrapGrid Background="Red"  Orientation="Vertical" Margin="0,0,40,0" />
                    </ItemsPanelTemplate>
                </GroupStyle.Panel>

                <GroupStyle.ContainerStyle>
                    <Style TargetType="GroupItem">
                        <Setter Property="Template">
                            <Setter.Value>
                                <ControlTemplate>
                                    <StackPanel>
                                        <ContentPresenter/>
                                        <ItemsPresenter/>
                                        <TextBlock Text="*** End of group ***"/>
                                    </StackPanel>
                                </ControlTemplate>
                            </Setter.Value>
                        </Setter>
                    </Style>
                </GroupStyle.ContainerStyle>

            </GroupStyle>
        </GridView.GroupStyle>               
    </GridView>

This almost works but after adding the container style, the grid of tiles no longer shows... the group header and 'End of group' textblock is showing, but I've lost the tile grid.

Can anyone spot what I'm doing wrong...?

Answer 1

What you are doing wrong? Replace VirtualizingStackPanel with its correspondent StackPanel and everything will work fine or move on Windows7 (the problem occurs on Vista). Btw. virtualization doesn't work on hierarchical objects like TreeView or DataGrid which uses grouping (GroupStyle). Thake a look on this.