Grouping GridView in Windows 8 Metro App

Question

Can someone give me some hints how to accomplish the grouping within a GridView for Metro Apps as shown in the Screenshot below.

Answer 1

I may have a solution. In my projet, I had to create a list of contacts in alphabetic order, like the People app.

I used a GridView (with this sample), a CollectionViewSource and a wrappanel I found in the WinRT XAML Toolkit (you can get with NuGet package or copy/paste the source code). It allow you to put your items in columns.

Example

ViewModel

class ContactListViewModel
    {

        public ContactListViewModel()
        {
            ContactSource = new CollectionViewSource();
            Contacts = new ObservableCollection<Contact>();

            Contacts.Add(new Contact("Gates","Bill"));
            Contacts.Add(new Contact("Bush","Georges"));
            Contacts.Add(new Contact("Obama","Barack"));
            Contacts.Add(new Contact("Hollande","François"));
            Contacts.Add(new Contact("Affleck","Ben"));
            Contacts.Add(new Contact("Allen","Woody"));
            Contacts.Add(new Contact("Hendrix","Jimi"));
            Contacts.Add(new Contact("Harrison", "Georges"));

            Contacts = new ObservableCollection<Contact>(Contacts.OrderBy(c => c.Name));
            ContactSource.Source = GetGroupsByLetter();
            ContactSource.IsSourceGrouped = true;

        }

        #region Contacts
        public ObservableCollection<Contact> Contacts
        {
            get;
            protected set;
        }

        public CollectionViewSource ContactSource
        {
            get;
            protected set;
        }
        #endregion


        internal List<GroupInfoList<object>> GetGroupsByLetter()
        {
            List<GroupInfoList<object>> groups = new List<GroupInfoList<object>>();

            var query = from item in Contacts
                        orderby ((Contact)item).Name
                        group item by ((Contact)item).Name[0] into g
                        select new { GroupName = g.Key, Items = g };
            foreach (var g in query)
            {
                GroupInfoList<object> info = new GroupInfoList<object>();
                info.Key = g.GroupName;
                foreach (var item in g.Items)
                {
                    info.Add(item);
                }
                groups.Add(info);
            }

            return groups;
        }

        public class GroupInfoList<T> : List<object>
        {

            public object Key { get; set; }


            public new IEnumerator<object> GetEnumerator()
            {
                return (System.Collections.Generic.IEnumerator<object>)base.GetEnumerator();
            }
        }
}

View

 <DataTemplate x:Key="contactTemplate">
    <Grid Width="225" Height="75" Background="#55FFFFFF">
        <Grid Margin="10">
            <Grid.RowDefinitions>
                <RowDefinition/>
                <RowDefinition/>
            </Grid.RowDefinitions>
            <TextBlock VerticalAlignment="Center" HorizontalAlignment="Left" FontSize="20">
                <Run Text="{Binding FirstName}"/>
                <Run Text="{Binding Name}"/>
            </TextBlock>
            <TextBlock Grid.Row="1" VerticalAlignment="Center" HorizontalAlignment="Left" Text="{Binding Email}" FontSize="13" Foreground="#FFDDDDDD"/>
        </Grid>
    </Grid>
</DataTemplate>

<DataTemplate x:Key="letterTemplate">
    <Grid Margin="5,0,0,5" Width="225">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <TextBlock Text="{Binding Key}" Style="{StaticResource GroupHeaderTextStyle}"  VerticalAlignment="Center"/>
        <Rectangle Grid.Row="1" Fill="#BBEEEEEE" Height="1" Margin="0,7,0,0"/>
    </Grid>
</DataTemplate>
</Page.Resources>



<!--
This grid acts as a root panel for the page that defines two rows:
* Row 0 contains the back button and page title
* Row 1 contains the rest of the page layout
-->
<Grid Style="{StaticResource LayoutRootStyle}">
    <Grid.RowDefinitions>
        <RowDefinition Height="140"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <!-- Back button and page title -->
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Button x:Name="backButton" Click="GoBack" Style="{StaticResource BackButtonStyle}" Opacity="0"/>
        <TextBlock x:Name="pageTitle" Grid.Column="1" Text="Manager" Style="{StaticResource PageHeaderTextStyle}"/>
    </Grid>

    <GridView Grid.Row="1"
        ItemsSource="{Binding Path=ContactSource.View}"
        SelectionMode="Multiple"
        IsSwipeEnabled="false"
        IsItemClickEnabled="True"
        Padding="116,10,40,46"
        ItemTemplate="{StaticResource contactTemplate}">

        <GridView.ItemsPanel>
            <ItemsPanelTemplate>
                <local:WrapPanel Orientation="Vertical"/>
            </ItemsPanelTemplate>
        </GridView.ItemsPanel>

        <GridView.GroupStyle>
            <GroupStyle HeaderTemplate="{StaticResource letterTemplate}">
                <GroupStyle.Panel>
                    <ItemsPanelTemplate>
                        <VariableSizedWrapGrid Orientation="Vertical" Margin="0,0,80,0"/>
                    </ItemsPanelTemplate>
                </GroupStyle.Panel>
            </GroupStyle>
        </GridView.GroupStyle>
    </GridView>
</Grid>

Answer 2

It can't be done using the default grid view styles.

You may have to use one none-grouped item list and add special items with different item template ...

Sorry

Answer 3

I would add the headers as items to the gridview, and use a TemplateSelector to display the elements the right way...

Answer 4

http://code.msdn.microsoft.com/windowsapps/GroupedGridView-77c59e8e