//write by wenhui.org
using System;
using System.IO;
using System.Text;
using System.Collections;

namespace PDFGenerator
{

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();

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;
}

static void Main(string[] args)
{
    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= "(http://www.wenhui.org)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();
}
}
}