Rob Robertson

Generate Dynamic iTextSharp PDF Documents from ASP.Net

robrobertson — Mon, 15 Jun 2009 21:02:24 +0000

Here’s two examples to dynamically create PDF’s using iTextSharps’ HTML Parser: in the browser and also a method to write the pdf to disk.

using System;
using System.Web;
using System.Web.UI;
using System.IO;
using System.Xml;
using iTextSharp.text;
using iTextSharp.text.html;
using iTextSharp.text.pdf;

namespace Web
{
    public partial class iTextSharpDemo : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            //Example HTML String
            string html = "Hello World!
Hello 2nd Page!";

            //Parse the HTML to PDF and Write PDF to disk
            WritePdf(html, @"c:\temp\share\mypdf.pdf");

            //Parse the HTML to PDF and write PDF bytes to browser via the outputstream
            MemoryStream m = CreatePdf(html);
            Response.ContentType = "application/pdf";
            Response.OutputStream.Write(m.GetBuffer(), 0, m.GetBuffer().Length);
            Response.OutputStream.Flush();
            Response.OutputStream.Close();
        }

        protected void WritePdf(string html, string destination)
        {
            MemoryStream ms = CreatePdf(html);

            FileStream fs = File.OpenWrite(destination);
            fs.Write(ms.GetBuffer(), 0, ms.GetBuffer().Length);
            fs.Close();
            ms.Close();
        }

        public static MemoryStream CreatePdf(string html)
        {
            MemoryStream m = new MemoryStream();

            try
            {
                Document document = new Document(PageSize.LETTER);
                PdfWriter.GetInstance(document, m);

                StringReader sr = new StringReader(html);
                XmlTextReader xtr = new XmlTextReader(sr);

                document.Open();

                HtmlParser.Parse(document, xtr);

                xtr.Close();
                document.Close();
            }
            catch (Exception ex)
            {
                System.Diagnostics.EventLog.WriteEntry("Application", ex.Message);
                throw ex;
            }

            return m;
        }

    }
}

Taking an ASP.Net Application Offline with an Outage Message

robrobertson — Mon, 30 Mar 2009 15:48:37 +0000

App_offline.htm is an easy, but not widely published, method to take your favorite ASP.Net Web Application offline and present a friendly outage message to your users. Simply create an outage message with your downtime info formatted in clear, readable html. Copy the file to the root of your website, and any requests will be redirected to this file.

iTextSharp – 401 Error when parsing images!

robrobertson — Thu, 06 Nov 2008 22:35:17 +0000

When using the html parser to convert a web page into PDF and also using an image tag to an IIS server that has Integrated Authentication enabled, you will receive: The remote server returned an error: (401) Unauthorized.

The easy solution is to find the GetImage(Uri url) method and add the default credentials to the WebRequest after it is created. These can be found in the itextsharp.txt.pdf.codec namespace in the following classes: BmpImage, GifImage, and PngImage.

WebRequest wr = WebRequest.Create(url);
wr.Credentials = CredentialCache.DefaultCredentials;
isp = wr.GetResponse().GetResponseStream();

Since iTextSharp is Open Source, it was easy to download the code, isolate the error, and quickly add a line of code for the authentication. Now, it’s time to submit the change to the iTextSharp project on SourceForge.

iTextSharp + NewPage -> “The document has no pages”

robrobertson — Tue, 28 Oct 2008 21:37:38 +0000

The constructor for an iTextSharp Pdf document doesn’t require the page size to be initialized and it does not default to a lovely letter sized page, therefore, attempting to add a new page to the document may result in an exception of “The document has no pages.”

When creating a document, always specify the page size such as:

Document document = new Document(PageSize.LETTER);

Using the HTML parser to generate a pagebreak in the Pdf file requires the simple tag:

Unfortunately, the HTML pagebreak,

, isn’t supported, but it should be fairly easy to add this functionality to the parser if needed.

MS SQL Insert Statement Generator

robrobertson — Thu, 04 Sep 2008 17:23:29 +0000

Narayana Vyas Kondreddi has created a wonderful stored procedure for MS SQL Server that will easily, quickly, and accurately create your SQL insert scripts for your next migration. He has two versions (SQL 2000 and 2005) of the sp_generate_inserts stored procedure along with a host of other neat T-SQL code scripts.

MSBuild and Quotation Marks “!!”

robrobertson — Thu, 04 Sep 2008 01:10:08 +0000

To publish a web site using Team Build, I added this task:

This returned an annoying “Invalid Number of Parameters” error. Since my path contained a space in it, I needed to include it in quotation marks. In order to escape the quotes, MSDN has a handy article on Escaping Special Characters in MSBuild. Looking up an ASCII table reveals that the quotation mark is Hex 22, so our new successful task is:

Extension Methods and Linq to SQL

robrobertson — Thu, 21 Aug 2008 20:25:12 +0000

Using Extension Methods with Linq to SQL is easy and handy to use! To change the insert behavior on the Linq to SQL object without having to use a stored procedure and create a business object around the l2s object, create an Extension Method. This example only insert users that haven’t already been added. Now, ToolUserInfo.Insert() is ready to be called.

public static void Insert(this ToolUserInfo userInfo)
{
//Create a DB Context
DataClassDataContext db = new DataClassDataContext();

// Get a list of existing tool users
var ToolUsers =
      (from u in db.R2ToolUserInfos
       select u.UserId);

if (!ToolUsers.Contains(userInfo.UserId))
{
    db.ToolUserInfos.InsertOnSubmit(userInfo);
    db.SubmitChanges();
}
}

ProperCase Function in .Net

robrobertson — Thu, 21 Aug 2008 17:49:13 +0000

There’s no need to roll your own proper case function in .Net! The ToTitleCase Method in the TextInfo class will format your name to the customs of the current culture. In general, only the first letter is uppercased and the remainder is lowercased. Also, it will not format a word if all the characters are uppercased (to not interfere with abbreviations). Our names were all captialized so I added ToLower, however that will cause any suffixes such as “III” to be formated as “Iii”.

 

public static string ProperCase(string input)

{

return Thread.CurrentThread.CurrentCulture.TextInfo.ToTitleCase(input.ToLower());

}

Pismo File Mount Audit Package (pfmap) – Best ISO Mount!

robrobertson — Mon, 18 Aug 2008 16:55:33 +0000

While the most common search terms don’t return this software at the top of the list, this is simply the best ISO file mounter available today (and free!). Sorry MagicISO but, pfmap lets me right click on the ISO and either mount it as a drive letter or (my favorite) perform a quick mount that makes the image appear as part of your current directory structure.

Head over to Pismo Techic, and try out pfmap.

Reflector .Net’s Decompiler Saves The Day!

robrobertson — Fri, 11 Apr 2008 22:24:38 +0000

The upgrade from Team Foundation Server 2005 to 2008 requires that all custom Team Build Tasks be recompiled with the latest assemblies. Unfortunately, code to these precious tasks was nowhere to be found. Before starting to rewrite the tasks from scratch, a quick search turned up Lutz Roeder’s Reflector for .Net. In addition to exploring all the classes in a .Net assembly, it fully decompiles .Net assemblies! The result is a working solution and project file complete with beautiful code.