C# 在以PDF格式保存到光盘之前，如何设置RDLC报告的边距？

我正在尝试使用以下代码以PDF格式将RDLC报告保存到光盘

    this.RequestViewer.SetPageSettings(Utility.Generate_Window_Control.funcSetReportMargin());
        byte[] bytes = RequestViewer.LocalReport.Render(

            "PDF", null, out mimeType, out encoding, out filenameExtension,
            out streamids, out warnings);

        using (FileStream fs = new FileStream("D:\\output.pdf", FileMode.Create))
        {

            fs.Write(bytes, 0, bytes.Length);
        }

并使用此功能设置报告页边距

    public static System.Drawing.Printing.PageSettings funcSetReportMargin()
   {
       System.Drawing.Printing.PageSettings pg = new System.Drawing.Printing.PageSettings();
       pg.Margins.Top = 10;
       pg.Margins.Bottom = 10;
       pg.Margins.Left = 0;
       pg.Margins.Right = 0;
       return pg;
   }

该函数在PrintPreview中运行良好，但当我将其保存为pdf时，它会打印空白页面。请指导我怎么做