ViewModel.vb

Imports System.Collections.ObjectModel

Namespace HierarchicalDataTemplate

    Public Class ViewModel

        Public Property MyData As Data

        Public Property SelectedItem As Object

        Public Sub New()
            MyData = New Data()
        End Sub
    End Class

    Public Class Data

        Public Property Categories As ObservableCollection(Of Category)

        Public Sub New()
            Categories = New ObservableCollection(Of Category)()
            Dim subitems As ObservableCollection(Of Item) = New ObservableCollection(Of Item)()
            subitems.Add(New Item() With {.ItemName = "Chair", .Description = "A red chair."})
            subitems.Add(New Item() With {.ItemName = "Table", .Description = "An old table."})
            Categories.Add(New Category() With {.CategoryName = "Furniture", .Items = subitems})
            Dim books As ObservableCollection(Of Item) = New ObservableCollection(Of Item)()
            books.Add(New Item() With {.ItemName = "Dictionary", .Description = "My old French-English Dictionary"})
            Categories.Add(New Category() With {.CategoryName = "Books", .Items = books})
        End Sub
    End Class

    Public Class Category

        Public Property CategoryName As String

        Public Property Description As String

        Public Property Items As ObservableCollection(Of Item)
    End Class

    Public Class Item

        Public Property ItemName As String

        Public Property Description As String
    End Class
End Namespace