asp生成PDF不使用插件

using System.IO;
using System.Text ;

public partial class Default2 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
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("D:\\myPDF.pdf");

static MemoryStream mPDF = new MemoryStream();

static void ConvertToByteAndAddtoStream(string strMsg)
{

Byte[] buffer = null;
buffer = ASCIIEncoding.ASCII.GetBytes(strMsg);
mPDF.Write(buffer, 0, buffer.Length);
buffer = null;
}

static 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;
}
protected void Button1_Click(object sender, EventArgs e)
{
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
strPDFMessage = "(PDF test)Tj\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);

mPDF.Close();
pPDF.Close();

}