从WebAPI响应创建PDF

Question

嘿伙计们希望你们都做得很好，我的问题就是我想从我的WebAPI响应中返回一个PDF文件，这是我用来获取创建pdf文件的响应的代码。

[Route("Reporte")]
    public async Task<HttpResponseMessage> createReport(RequestIdSugeridoModel request)
    {
        Thread.CurrentThread.CurrentCulture = culture;
        ResponseEncabezadoSugeridoModel encabezado = new ResponseEncabezadoSugeridoModel();
        List<ResponseDetalleSugeridoModel> detalle = new List<ResponseDetalleSugeridoModel>();
        SolicitudSugeridoController solicitud;
        Document document;
        System.IO.MemoryStream memoryStream = new System.IO.MemoryStream();

        try
        {
            using (SqlConnection CN_SGE = new SqlConnection(CNSGE))
            {
                solicitud = new SolicitudSugeridoController();
                await CN_SGE.OpenAsync();
                await solicitud.GetObtenEncabezadoSugerido(CN_SGE, encabezado, request);
                await solicitud.GetObtenDetSugerido(CN_SGE, detalle, request);
            }

            //start with pdf creation
            document = new Document(PageSize.LETTER);
            PdfWriter writer = PdfWriter.GetInstance(document, memoryStream);
            document.AddTitle("Reporte de Compras");
            document.AddCreator("Disisa");
            document.Open();

            // set standard font type and size
            iTextSharp.text.Font _standardFont = new iTextSharp.text.Font(iTextSharp.text.Font.HELVETICA, 9, iTextSharp.text.Font.NORMAL, Color.BLACK);
            //write document header
            document.Add(new Paragraph(encabezado.razonsocial));
            //document.Add(Chunk.NEWLINE);
            document.Add(new Paragraph("COMPRAS SUGERIDAS"));
            //document.Add(Chunk.NEWLINE);
            document.Add(new Paragraph(encabezado.nombresucursal));
            //document.Add(Chunk.NEWLINE);

            // Create table for pdf
            PdfPTable tableHeader = new PdfPTable(2);
            PdfPCell cellFolio = new PdfPCell(new Phrase("FOLIO: " + encabezado.folio + " " + "SEMANA: " + encabezado.semana, _standardFont));
            PdfPCell cellFecha = new PdfPCell(new Phrase("FECHA: " + encabezado.fecha, _standardFont));
            // set border and aligment for the cells
            cellFolio.Border = 0;
            cellFolio.HorizontalAlignment = 0; // 0=left, 1=center, 2=right
            cellFecha.Border = 0;
            cellFecha.HorizontalAlignment = 2; // 0=left, 1=center, 2=right
                                               // Add cells to the table header
            tableHeader.AddCell(cellFolio);
            tableHeader.AddCell(cellFecha);

            PdfPTable mainTable = new PdfPTable(8);
            mainTable.HorizontalAlignment = 1;
            // here we will add table headers for report details
            PdfPCell cellProducto = new PdfPCell(new Phrase("NOMBRE DEL PRODUCTO", _standardFont));
            PdfPCell cellExistencia = new PdfPCell(new Phrase("EXISTENCIA", _standardFont));
            PdfPCell cellMes1 = new PdfPCell(new Phrase(encabezado.mes1, _standardFont));
            PdfPCell cellMes2 = new PdfPCell(new Phrase(encabezado.mes2, _standardFont));
            PdfPCell cellMes3 = new PdfPCell(new Phrase(encabezado.mes3, _standardFont));
            PdfPCell cellMes4 = new PdfPCell(new Phrase(encabezado.mes4, _standardFont));
            PdfPCell cellSugerido = new PdfPCell(new Phrase("SUGERIDO", _standardFont));
            PdfPCell cellObservacion = new PdfPCell(new Phrase("OBSERVACIONES", _standardFont));

            mainTable.AddCell(cellProducto);
            mainTable.AddCell(cellExistencia);
            mainTable.AddCell(cellMes1);
            mainTable.AddCell(cellMes2);
            mainTable.AddCell(cellMes3);
            mainTable.AddCell(cellMes4);
            mainTable.AddCell(cellSugerido);
            mainTable.AddCell(cellObservacion);

            foreach (var item in detalle)
            {
                mainTable.AddCell(item.nombreproducto);
                mainTable.AddCell(item.existencia.ToString());
                mainTable.AddCell(item.mes1.ToString());
                mainTable.AddCell(item.mes2.ToString());
                mainTable.AddCell(item.mes3.ToString());
                mainTable.AddCell(item.mes4.ToString());
                mainTable.AddCell(item.sugerido.ToString());
                mainTable.AddCell(item.observacion);
            }

            // Add tableHeader to document
            document.Add(tableHeader);
            // Add mainTable to document
            document.Add(mainTable);

            //return Request.CreateResponse(System.Net.HttpStatusCode.OK, document);
            memoryStream.Position = 0;
            HttpResponseMessage response = new HttpResponseMessage(System.Net.HttpStatusCode.OK)
            {
                Content = new StreamContent(memoryStream)
                {
                    Headers = {
                        ContentType = new MediaTypeHeaderValue(System.Net.Mime.MediaTypeNames.Applicat‌​ion.Pdf),
                        ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = "PdfFileName.pdf" }
                    }
                }
            };

            // close document and writer
            document.Close();
            writer.Flush();

            return response;
        }
        catch (ApplicationException ex)
        {
            ErrorModel _errors = new ErrorModel();
            _errors.message = ex.Message;
            return Request.CreateResponse(System.Net.HttpStatusCode.InternalServerError, _errors);
        }
        catch (Exception ex)
        {
            ErrorModel _errors = new ErrorModel();
            _errors.message = ex.Message;
            return Request.CreateResponse(System.Net.HttpStatusCode.InternalServerError, _errors);
        }
    }

现在，当我用邮递员测试它时，我唯一得到的回答是：

{
"PageNumber": 0,
"LeftMargin": 36,
"RightMargin": 36,
"TopMargin": 36,
"BottomMargin": 36,
"Left": 36,
"Right": 576,
"Top": 756,
"Bottom": 36,
"PageSize": {
    "Type": 30,
    "Chunks": [],
    "Width": 612,
    "Height": 792,
    "Rotation": 0
},
"JavaScript_onLoad": null,
"JavaScript_onUnLoad": null,
"HtmlStyleClass": null

}

我怎样才能做到这一点？

提前致谢。我已经按照现在的方式更新了代码，并提供了@ckuri提供的答案