Private Function SaveAsDXF(ByVal DrawingDoc As Inventor.DrawingDocument, ByVal Filename As String) As Boolean
        Try
            Dim invApp As Inventor.Application = DrawingDoc.Parent

            ' PDF Übersetzer Add-In.
            Dim DXFAddIn As Inventor.TranslatorAddIn
            DXFAddIn = invApp.ApplicationAddIns.ItemById("{C24E3AC4-122E-11D5-8E91-0010B541CD80}")

            Dim Context As Inventor.TranslationContext
            Context = invApp.TransientObjects.CreateTranslationContext
            Context.Type = Inventor.IOMechanismEnum.kFileBrowseIOMechanism

            ' Erstelle Name 
            Dim Options As Inventor.NameValueMap
            Options = invApp.TransientObjects.CreateNameValueMap

            ' Erstelle Medium
            Dim DataMedium As Inventor.DataMedium
            DataMedium = invApp.TransientObjects.CreateDataMedium
            Dim oReferencedDoc As Document
            oReferencedDoc = DrawingDoc.ReferencedDocuments.Item(1)
            Dim customPropSet As PropertySet
            customPropSet = DrawingDoc.PropertySets.Item("Inventor User Defined Properties")
            Dim ZnNr As [Property]
            ZnNr = customPropSet.Item("Zeichnungsnummer")

            'Speichern
            Dim dir As String = ""
            Dim fb As New FolderBrowserDialog
            With fb
                .Description = "Speicherort"
                If .ShowDialog = System.Windows.Forms.DialogResult.OK Then
                    txtPath.Text = .SelectedPath
                End If
            End With

            'Zieldateinamen 
            DataMedium.FileName = txtPath.Text & "\" & ZnNr.Value & ".dxf"

            'Dokument veröffentlichen
            Call DXFAddIn.SaveCopyAs(DrawingDoc, Context, Options, DataMedium)


            Return True
        Catch ex As Exception
            Return False
        End Try
    End Function