[2005] Collection, ArrayList or Hashtable?

[jmcilhinney]

OK, now I see what you're getting at (I think). Yeah, it seems like what you want is a Generic.Dictionary(Of String, Generic.Dictionary(Of Integer, IITTrack)). Again, I'd say that hiding it inside a class would be a good idea. Then you could provide a an Item property something like this:

Private tracksByAlbum As New Generic.Dictionary(Of String, Generic.Dictionary(Of Integer, IITTrack))
 
Public Property Item(ByVal albumName As String, ByVal trackID As Integer) As IITTrack
    Get
        Dim tracksByID As Generic.Dictionary(Of Integer, IITTrack) = Me.tracksByAlbum(albumName)
 
        If tracksByID Is Nothing Then
            Return Nothing
        Else
            Return tracksByID(trackID)
        End If
    End Get
    Set(ByVal value As IITTrack)
         Dim tracksByID As Generic.Dictionary(Of Integer, IITTrack) = Me.tracksByAlbum(albumName)
 
        If tracksByID Is Nothing Then
            tracksByID = New Generic.Dictionary(Of Integer, IITTrack)
            Me.tracksByAlbum.Add(albumName, tracksByID)
        End If
 
        tracksByID(trackID) = value
    End Set
End Property