Imports CrystalDecisions.Shared
Imports CrystalDecisions.CrystalReports.Engine
Imports CrystalDecisions.Web.Design

        Public Shared Function BuildPdf(ByVal rpt As ReportDocument, ByVal vpath As String) As String
            Dim dFileDOpts As DiskFileDestinationOptions
            Dim eOpts As New ExportOptions
            Dim eFile As String, filename As String
            Dim webcontext As HttpContext = System.Web.HttpContext.Current
            Dim pdfName As String

            Try
                '//
                '// si effettua l'eportazione del report in formato pdf, poi si esegue una copia di tale file pdf
                '// sulla working dir dedicata alla sessione in modo da consentire il download
                '//
                eOpts = rpt.ExportOptions
                eOpts.ExportDestinationType = ExportDestinationType.DiskFile
                eOpts.ExportFormatType = ExportFormatType.PortableDocFormat

                pdfName = webcontext.Server.MapPath(vpath)

                dFileDOpts = New DiskFileDestinationOptions
                eFile = pdfName
                dFileDOpts.DiskFileName = eFile
                eOpts.DestinationOptions = dFileDOpts
                '--> generazione del file PDF
                rpt.Export()
            Catch ex As Exception
        ...................
        ..............
            End Try
            Return pdfName
        End Function