控制水晶报表只能导出PDF

    ds_Leader.Tables.Add(dt);
            ds_Leader.Tables[0].TableName = "dt";//
            ds_Leader.Tables.Add(dt1);
            ds_Leader.Tables[1].TableName = "dt1";//

            //ReportDocument rtd = new ReportDocument();
            //string path = Server.MapPath("\\QueryStatistic\\CrystalReport\\ReserveSummaryReport.rpt");
            //rtd.Load(path);
            //rtd.SetDataSource(ds_Leader);
            //CrystalReportViewer1.ReportSource = rtd;
            CommonOper.PDFOperate pdfOperate = new CommonOper.PDFOperate();
            CrystalDecisions.CrystalReports.Engine.ReportDocument rptDoc = new ReportDocument();
            rptDoc.Load(this.Server.MapPath("\\QueryStatistic\\CrystalReport\\ReserveSummaryReport.rpt"));
            rptDoc.SetDataSource(ds_Leader);
            CrystalDecisions.Shared.DiskFileDestinationOptions objFile = new CrystalDecisions.Shared.DiskFileDestinationOptions();
            objFile.DiskFileName = this.Server.MapPath("myTest.pdf");
            rptDoc.ExportOptions.ExportDestinationType = ExportDestinationType.DiskFile;
            rptDoc.ExportOptions.DestinationOptions = objFile;
            rptDoc.ExportOptions.ExportFormatType = ExportFormatType.PortableDocFormat;
            rptDoc.Export();
            string error = "pdf生成水印错误";
            bool IsRight = pdfOperate.AddTextWaterMark("myTest.pdf", ref error, DateTime.Now.ToString(), 0);
            Response.ClearContent();
            Response.ClearHeaders();
            Response.ContentType = "application/pdf";
            Response.WriteFile(objFile.DiskFileName);
            Response.Flush();
            Response.Close();