Question

Is it possible to group items in a ItemsControl or Listbox in Silverlight? These controls are bound to a DomainDataSource.

Or are there any 3rd party controls that do this?

UPDATE:

This is the sort of UI I am trying to create.

Answer 1

You can do this by using nested ItemsControls bound to a PagedCollectionView.

Say I have a datasource – MyItems – with fields: Category, Section and Option. I can create a PagedCollectionView from an IEnumerable(of MyItems) and tell it which fields to group by.

Dim original As IEnumerable(Of MyItems) = GetMyItems()

Dim pcv = New PagedCollectionView(original)

pcv.GroupDescriptions.Add(New PropertyGroupDescription("Category"))
pcv.GroupDescriptions.Add(New PropertyGroupDescription("Section"))

Then I bind my first ItemsControl to the PagedCollectionView

hisMyItems.ItemsSource = pcv.Groups

The PCV creates a nested hierachy like:

-Name
    -Items

where Name is the value in the grouped field and Items contains the rows/objects in that grouping. I guess you could also create the PCV in xaml if you prefer.

The xaml would look something like:

<controls:HeaderedItemsControl x:Name="hisMyItems" Header="{Binding Name}" ItemsSource="{Binding Items}" >
    <controls:HeaderedItemsControl.ItemTemplate>
        <DataTemplate>

            <controls:HeaderedItemsControl Header="{Binding Name}" ItemsSource="{Binding Items}" ItemsPanel="{StaticResource ItemsPanelTemplate1}" >
                <controls:HeaderedItemsControl.ItemTemplate>
                    <DataTemplate>
                        <Button Content="{Binding Option}" />
                    </DataTemplate>
                </controls:HeaderedItemsControl.ItemTemplate>
            </controls:HeaderedItemsControl>

        </DataTemplate>
    </controls:HeaderedItemsControl.ItemTemplate>
</controls:HeaderedItemsControl>

I hope that makes sense. I have tried to simplify things from my actual app but I could have made some mistakes in copying it over. Obviously you could use normal ItemsControls or other controls too and customize with templates etc.