asp.net 导出pdf文件 请没帮助！

using System;using System.IO;using System.Text;using System.Collections;using System.Data;namespace aa{    /// <summary>    /// 导出PDF    /// </summary>    public class PDFGenerator    {        static float pageWidth = 594.0f;        static float pageDepth = 828.0f;        static float pageMargin = 30.0f;        static float fontSize = 20.0f;        static float leadSize = 10.0f;        static StreamWriter pPDF = new StreamWriter("E:\\myPDF.pdf");        static MemoryStream mPDF = new MemoryStream();        private void ConvertToByteAndAddtoStream(string strMsg)        {            Byte[] buffer = null;            buffer = ASCIIEncoding.ASCII.GetBytes(strMsg);            mPDF.Write(buffer, 0, buffer.Length);            buffer = null;        }        private string xRefFormatting(long xValue)        {            string strMsg = xValue.ToString();            int iLen = strMsg.Length;            if (iLen < 10)            {                StringBuilder s = new StringBuilder();                int i = 10 - iLen;                s.Append('0', i);                strMsg = s.ToString() + strMsg;            }            return strMsg;        }        public void ExportPdf(DataTable dt)        {            ArrayList xRefs = new ArrayList();            //Byte[] buffer=null;             float yPos = 0f;            long streamStart = 0;            long streamEnd = 0;            long streamLen = 0;            string strPDFMessage = null;            //PDF文档头信息             strPDFMessage = "%PDF-1.1\n";            ConvertToByteAndAddtoStream(strPDFMessage);            xRefs.Add(mPDF.Length);            strPDFMessage = "1 0 obj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = " < < /Length 2 0 R >>\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = "stream\n";            ConvertToByteAndAddtoStream(strPDFMessage);            ////////PDF文档描述             streamStart = mPDF.Length;            //字体             strPDFMessage = "BT\n/F0 " + fontSize + " Tf\n";            ConvertToByteAndAddtoStream(strPDFMessage);            //PDF文档实体高度             yPos = pageDepth - pageMargin;            strPDFMessage = pageMargin + " " + yPos + " Td\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = leadSize + " TL\n";            ConvertToByteAndAddtoStream(strPDFMessage);            //实体内容             for (int i = 0; i < dt.Rows.Count; i++)            {                for (int j = 0; j < dt.Columns.Count; j++)                {                    strPDFMessage = "(" + dt.Rows[i][j].ToString() + ")Tj\n" + "\n";                    ConvertToByteAndAddtoStream(strPDFMessage);                }            }            strPDFMessage = "ET\n";            ConvertToByteAndAddtoStream(strPDFMessage);            streamEnd = mPDF.Length;            streamLen = streamEnd - streamStart;            strPDFMessage = "endstream\nendobj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            //PDF文档的版本信息             xRefs.Add(mPDF.Length);            strPDFMessage = "2 0 obj\n" + streamLen + "\nendobj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            xRefs.Add(mPDF.Length);            strPDFMessage = "3 0 obj\n < </Type/Page/Parent 4 0 R/Contents 1 0 R>>\nendobj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            xRefs.Add(mPDF.Length);            strPDFMessage = "4 0 obj\n < </Type /Pages /Count 1\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = "/Kids[\n3 0 R\n]\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = "/Resources < </ProcSet[/PDF/Text]/Font < </F0 5 0 R>> >>\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = "/MediaBox [ 0 0 " + pageWidth + " " + pageDepth + " ]\n>>\nendobj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            xRefs.Add(mPDF.Length);            strPDFMessage = "5 0 obj\n < </Type/Font/Subtype/Type1/BaseFont/Courier/Encoding/WinAnsiEncoding>>\nendobj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            xRefs.Add(mPDF.Length);            strPDFMessage = "6 0 obj\n < </Type/Catalog/Pages 4 0 R>>\nendobj\n";            ConvertToByteAndAddtoStream(strPDFMessage);            streamStart = mPDF.Length;            strPDFMessage = "xref\n0 7\n0000000000 65535 f \n";            for (int i = 0; i < xRefs.Count; i++)            {                strPDFMessage += xRefFormatting((long)xRefs[i]) + " 00000 n \n";            }            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = "trailer\n < <\n/Size " + (xRefs.Count + 1) + "\n/Root 6 0 R\n>>\n";            ConvertToByteAndAddtoStream(strPDFMessage);            strPDFMessage = "startxref\n" + streamStart + "\n%%EOF\n";            ConvertToByteAndAddtoStream(strPDFMessage);            mPDF.WriteTo(pPDF.BaseStream);            //System.Web.HttpContext.Current.Response.Write(pPDF.BaseStream);             mPDF.Close();            pPDF.Close();        }    }}