GridView Grouping

        <GridView
            x:Name="itemGridView"
            AutomationProperties.AutomationId="ItemGridView"
            AutomationProperties.Name="Grouped Items"
            Grid.RowSpan="2"
            Padding="116,137,40,46"
            ItemsSource="{Binding Source={StaticResource groupedItemsViewSource}}"
            SelectionMode="None"
            IsSwipeEnabled="false"
            IsItemClickEnabled="True"
            ItemClick="ItemView_ItemClick">
            <GridView.ItemTemplate>
                <DataTemplate>
                    <Grid HorizontalAlignment="Left" Width="250" Height="250">
                        <Border Background="{StaticResource ListViewItemPlaceholderBackgroundThemeBrush}">
                            <Image Source="{Binding ImagePath}" Stretch="UniformToFill" AutomationProperties.Name="{Binding Title}"/>
                        </Border>
                        <StackPanel VerticalAlignment="Bottom" Background="{StaticResource ListViewItemOverlayBackgroundThemeBrush}">
                            <TextBlock Text="{Binding Title}" Foreground="{StaticResource ListViewItemOverlayForegroundThemeBrush}" Style="{StaticResource TitleTextBlockStyle}" Height="60" Margin="15,0,15,0"/>
                            <TextBlock Text="{Binding Subtitle}" Foreground="{StaticResource ListViewItemOverlaySecondaryForegroundThemeBrush}" Style="{StaticResource CaptionTextBlockStyle}" TextWrapping="NoWrap" Margin="15,0,15,10"/>
                        </StackPanel>
                    </Grid>
                </DataTemplate>
            </GridView.ItemTemplate>
            <GridView.ItemsPanel>
                <ItemsPanelTemplate>
                    <ItemsWrapGrid GroupPadding="0,0,70,0"  />
                </ItemsPanelTemplate>
            </GridView.ItemsPanel>
            <GridView.GroupStyle>
                <GroupStyle>
                    <GroupStyle.HeaderTemplate>
                        <DataTemplate>
                            <Grid Margin="1,0,0,6">
                                <Button Foreground="{StaticResource ApplicationHeaderForegroundThemeBrush}"
                                    AutomationProperties.Name="Group Title"
                                    Click="Header_Click"
                                    Style="{StaticResource TextBlockButtonStyle}" >
                                    <StackPanel Orientation="Horizontal">
                                        <TextBlock Text="{Binding Title}" Margin="3,-7,10,10" Style="{StaticResource HeaderTextBlockStyle}" TextWrapping="NoWrap" />
                                        <TextBlock Text="{StaticResource ChevronGlyph}" FontFamily="Segoe UI Symbol" Margin="0,-7,0,10" Style="{StaticResource SubheaderTextBlockStyle}" TextWrapping="NoWrap" />
                                    </StackPanel>
                                </Button>
                            </Grid>
                        </DataTemplate>
                    </GroupStyle.HeaderTemplate>
                </GroupStyle>
            </GridView.GroupStyle>
        </GridView>