Generate PDF documents from a HTML page using ASP.NET

Introduction

This project uses an HTML to PDF exe from ESP. Please read the GNU license agreement for more information. HTMLDOC is a desktop application to create PDF documents from a HTML page. I wrote some code to use it from a web application. The best used is from a Web Report to add a PRINT to PDF button to use the C# class.

Using the code

    public string Run(string sRawUrl)
    {            
        string sFileName = GetNewName();
        string sPage = Server.MapPath("" + sFileName + ".html");            
        string sUrlVirtual = sRawUrl;
        StringWriter sw = new StringWriter();

        Server.Execute(sUrlVirtual, sw);

        StreamWriter sWriter = File.CreateText(sPage);
        sWriter.WriteLine(sw.ToString());
        sWriter.Close();    

        System.Diagnostics.Process pProcess 
                             = new System.Diagnostics.Process();
        pProcess.StartInfo.FileName = m_sDrive + ":" + m_Directory + 
                                            "//ghtmldoc.exe";
        pProcess.StartInfo.Arguments = "--webpage --quiet " + sFontSize + 
                  m_sWaterMark + " --bodyfont Arial " + sLandScape + 
                  " -t pdf14 -f " + sFileName + ".pdf " + sFileName + ".html";
        pProcess.StartInfo.WorkingDirectory = m_sDrive + ":" + m_Directory;

        pProcess.Start();            

        return(sFileName + ".pdf");            
    }

The class PDFGenerator contains a public method called Run that will call the process hghtmldoc.exe with the arguments you choose. The most important part is to set a working directory where the Web application has permission to read, write and execute, otherwise the program won't work, and the function pProcess.Start will raise a Win32 Exception "access denied".

StreamWriter will save the page into a HTML file on the hard disk.

The file DisplayPDF.aspx and DisplayPDF.aspx.cs will do just that, displays the generated PDF file when ready.

        private void Page_Load(object sender, System.EventArgs e)
        {

            if ( Request.Params["File"] != null )
            {
                bool bRet = false;
                int iTimeout = 0;
                while ( bRet == false )
                {
                    bRet = CheckIfFileExist(Request.Params["File"].ToString());
                    Thread.Sleep(1000);
                    iTimeout++;
                    if ( iTimeout == 10 )
                        break;
                }

                if ( bRet == true )
                {
                    Response.ClearContent();
                    Response.ClearHeaders();
                    Response.ContentType = "Application/pdf";
                    try 
                    { 
                        Response.WriteFile( MapPath( "" + 
                                      Request.Params["File"].ToString() ) ); 
                        Response.Flush();
                        Response.Close();
                    }
                    catch 
                    { 
                        Response.ClearContent();  
                    }
                    
                }
                else
                {
                    if ( Request.Params["Msg"] != null )
                    {
                        LabelMsg.Text = Request.Params["Msg"].ToString();
                    }
                }
            }
        }

The page accepts a parameter, FILE, previously saved in the hard disk by StreamWriter. The Response.Redirect will include application/PDF, so the browser knows what kind of file is downloading and ask you to SAVE or OPEN. If you have Adobe plug-in installed on your browser, you'll be able to see the PDF from your browser.