WPF Databinding : Using CompositeCollection

The goal is to have a ComboBox whose ItemsSource should bind to more than one collection. In order to this, we make use of CompositeCollection as shown below.

XAML

<StackPanel> 
  <ComboBox Name="cb" ItemsSource="{Binding MoreThanOneCollection}"> 
 </ComboBox> 
 </StackPanel>

Code-behind

Private _moreThanOneCollection As New CompositeCollection

    Public Property MoreThanOneCollection() As CompositeCollection
        Get
            Return _moreThanOneCollection
        End Get
        Set(ByVal value As CompositeCollection)
            _moreThanOneCollection = value
        End Set
    End Property

    Private Sub Window_Loaded(ByVal sender As System.Object, _
                              ByVal e As System.Windows.RoutedEventArgs)
        Me.DataContext = Me 'set the datacontext
        BindData()
        BindMoreData()
    End Sub


    Sub BindMoreData()
        Dim data2 As New CollectionContainer
        data2.Collection = GetData().Reverse()
        'another set of data, just for the heck of it
        MoreThanOneCollection.Insert(0, data2)
    End Sub


    Sub BindData()
        Dim container = New CollectionContainer
        container.Collection = GetData() ' the first data
        MoreThanOneCollection.Add(container)
    End Sub

    Function GetData() As IEnumerable(Of String)
        Dim x As New ObservableCollection(Of String)
        x.Add("Item 1")
        x.Add("Item 2")
        x.Add("Item 3")
        Return x
    End Function

Just for practise purpose, I thought I would create the composite collection in code. This can also be done in XAML.