itextsharp swf embeded cannot be print

Question

        Dim r As Rectangle = New Rectangle(0, 0, 600, 400)
        Dim spec As PdfFileSpecification = PdfFileSpecification.FileEmbedded(writer, swfFile, "Post Event Report", Nothing)
        Dim annot As PdfAnnotation = PdfAnnotation.CreateScreen(writer, r, "test.swf", spec, "application/x-shockwave-flash", True)
        annot.Flags = PdfAnnotation.FLAGS_PRINT
        writer.AddAnnotation(annot)