Filtering for Dynamic Blocks using XData - Need help with XData.ASArray

[apitcher799568]

I am trying to filter for a dynamic block using xdata. I found this post by Kean Walmsley going over the process, but I haven't been able to make it work for me. The code he has is in C#, which I'm not familiar with (I code very rarely).

This is what I have so far:

        Dim doc As Document = Application.DocumentManager.MdiActiveDocument
        Dim db As Database = doc.Database
        Dim ed As Editor = doc.Editor


        Using tr As Transaction = doc.TransactionManager.StartTransaction()

            Dim bt As BlockTable = tr.GetObject(db.BlockTableId, OpenMode.ForWrite)

            For Each bid In bt
                Dim btr2 As BlockTableRecord = tr.GetObject(bid, OpenMode.ForWrite)
                If Not btr2.Name = "PointMarker" AndAlso IsDBNull(btr2.XData) = False Then
                    Dim TypeValArr() As TypedValue = btr2.XData.AsArray
                    For i = 0 To TypeValArr.Length
                        Dim TypeVal As String = TypeValArr(i)
                        If TypeVal.GetTypeCode = DxfCode.ExtendedDataRegAppName Then
                            If TypeVal.ToString = "AcDbBlockRepBTag" Then
                                For j = i + 1 To TypeValArr.Length
                                    TypeVal = TypeValArr(j)
                                    If TypeVal.GetTypeCode = DxfCode.ExtendedDataRegAppName Then
                                        i = j - 1
                                        Exit For
                                    End If
                                    If TypeVal.GetTypeCode = DxfCode.ExtendedDataHandle Then
                                        If TypeVal.ToString = "PointMarker" Then
                                            Dim blockref As BlockReference = btr2.Id.GetObject(OpenMode.ForWrite)
                                            Dim xpos As Double = blockref.Position.X
                                            Dim ypos As Double = blockref.Position.Y
                                            Dim zpos As Double = blockref.Position.Z
                                            Dim scalefactor As Double = blockref.ScaleFactors.X
                                            blockref.ScaleFactors() = New Scale3d(sf)
                                            Dim ac As AttributeCollection = blockref.AttributeCollection
                                            For Each att As ObjectId In ac
                                                Dim attr As DBObject = att.GetObject(OpenMode.ForWrite)
                                                If TypeOf attr Is AttributeReference Then
                                                    Dim ar As AttributeReference = att.GetObject(OpenMode.ForWrite)
                                                    ar.TransformBy(Matrix3d.Scaling(1 / scalefactor, New Point3d(xpos, ypos, zpos)))
                                                    ar.TransformBy(Matrix3d.Scaling(sf, New Point3d(xpos, ypos, zpos)))
                                                End If
                                            Next
                                            i = TypeValArr.Length - 1
                                            Exit For
                                        End If
                                    End If
                                    j = j + 1
                                Next
                            End If
                        End If
                        i = i + 1
                    Next

                End If
            Next

tr.Commit()

End Using

I am stuck on the "Dim TypeValArr As Array = btr2.XData.AsArray" part. It continually causes a fatal error when the code runs. Should I be declaring this differently?