using Microsoft.Office.Interop.Visio;



private static void ConvertVSD(string inputFile, string outputFile)

{

    ApplicationClass visio = new ApplicationClass();

    Document doc = null;



    try

    {

        //apro il documento

        doc = visio.Documents.Open(inputFile);



        //definisco i parametri per la conversione

        VisFixedFormatTypes formato = VisFixedFormatTypes.visFixedFormatPDF;

        VisDocExIntent intent = VisDocExIntent.visDocExIntentPrint;

        VisPrintOutRange printRange = VisPrintOutRange.visPrintAll;

        object paramMissing = Type.Missing;



        //converto in PDF

        doc.ExportAsFixedFormat(formato, outputFile, intent,

                                printRange, 0, 100000, false,

                                true, false, false, true, paramMissing);

    }

    catch (Exception exe)

    {

        Console.WriteLine(exe.Message + exe.StackTrace);

    }

    finally

    {

        if (doc != null)

        {

            doc.Close();

            doc = null;

        }

        if (visio != null)

        {

            visio.Quit();

            visio = null;

        }



        GC.Collect();

        GC.WaitForPendingFinalizers();

        GC.Collect();

        GC.WaitForPendingFinalizers();

    }

}