VB CAD to PDF converter (DWG, DXF, DGN, DWF, and RVT)

Imports System
Imports System.Drawing
Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices
Imports pdftron
Imports pdftron.Common
Imports pdftron.PDF
Imports pdftron.SDF

Namespace CAD2PDFTestVB
    Class Class1
        Private Shared pdfNetLoader As pdftron.PDFNetLoader = pdftron.PDFNetLoader.Instance()

        Private Shared Function IsRVTFile(ByVal input_file_name As String) As Boolean
            Dim rvt_input As Boolean = False

            If input_file_name.Length > 2 Then

                If input_file_name.Substring(input_file_name.Length - 3, 3) = "rvt" Then
                    rvt_input = True
                End If
            End If

            Return rvt_input
        End Function

        Shared Sub Main(ByVal args As String())
            PDFNet.Initialize(PDFTronLicense.Key)
            PDFNet.AddResourceSearchPath("../../../../../Lib/")

            If Not CADModule.IsModuleAvailable() Then
                Console.WriteLine()
                Console.WriteLine("Unable to run CAD2PDFTest: PDFTron SDK CAD module not available.")
                Console.WriteLine("---------------------------------------------------------------")
                Console.WriteLine("The CAD module is an optional add-on, available for download")
                Console.WriteLine("at http://www.pdftron.com/. If you have already downloaded this")
                Console.WriteLine("module, ensure that the SDK is able to find the required files")
                Console.WriteLine("using the PDFNet::AddResourceSearchPath() function.")
                Console.WriteLine()
            End If

            Dim input_path As String = "../../../../TestFiles/CAD/"
            Dim output_path As String = "../../../../TestFiles/Output/"
            Dim input_file_name As String = "construction drawings color-28.05.18.dwg"
            Dim output_file_name As String = "construction drawings color-28.05.18.pdf"

            If args.Length <> 0 Then
                input_file_name = args(0)
                output_file_name = input_file_name & ".pdf"
            End If

            Console.WriteLine("Example cad:")

            Try

                Using pdfdoc As PDFDoc = New PDFDoc()

                    If IsRVTFile(input_file_name) Then
                        Dim opts As CADConvertOptions = New CADConvertOptions()
                        opts.SetPageWidth(800)
                        opts.SetPageHeight(600)
                        opts.SetRasterDPI(150)
                        pdftron.PDF.Convert.FromCAD(pdfdoc, input_path & input_file_name, opts)
                    Else
                        pdftron.PDF.Convert.FromCAD(pdfdoc, input_path & input_file_name, Nothing)
                    End If

                    pdfdoc.Save(output_path & output_file_name, SDFDoc.SaveOptions.e_remove_unused)
                End Using

                Console.WriteLine("Done.")
            Catch e As PDFNetException
                Console.WriteLine(e.Message)
            End Try
            PDFNet.Terminate()
        End Sub
    End Class
End Namespace