Welcome to Imar.Spaanjaars.Com

Today Microsoft released beta 2 of Visual Studio 2008.

A couple of days ago I received an e-mail from a visitor to my site. He wanted to know a couple of things about the design and architecture of my site.

Over the past couple of months I received a number of questions related to sorting with the classes from my N-Layer Design article series and the GridView. The good thing is: it isn't that hard; it's just that you need to know how to do it....

Today my web site has reached a very interesting milestone: It registered the 500,000th article view. A good moment to look back a bit, and see what happened with my site during the past few years.

My on-line friend Peter has been so kind to translate the code for the Contact Manager Application from my articles about N-Layer Design to Visual Basic.NET.

In case you hadn't noticed yet: Beta 1 of Visual Studio Orcas is out....

Quite often I have discussed the impossibility of joining data from a database with that of the file system. I discussed it with my team members, mentioned it in trainings and wrote about it recently in this article.

Being able to join data from a database with other data from a file system could be very useful though.

Ever since I posted my first article on this web site, on September 22 2003, I have enjoyed feedback from you, my reader. For me, it was the best (and often only) way to get in touch with you, and accept article requests, questions and general feedback about my site.

Update!! 12-24-2008 - I have written a new series on N-Layer design as a major follow up to this one. It builds on the foundation created in this first series, but digs much deeper into concepts like Validation, Sorting, Paging, Concurrency and Security. You can check out the new series here.

Update!! 04-25-2007 - There is now also a VB.NET version of the code available for download. You find the download at the end of this article. For more information about the translation, check out this blog post.

This is part three of the article series "Building Layered Web Applications" that shows you how to build N-Layer applications with Microsoft ASP.NET 2.0. These articles teach you how to design, build and use custom business objects in your web application. The target audience for this series are developers that are ready to make the switch from using SqlDataSource controls to ObjectDataSource controls with custom business objects. Experience with ASP.NET 2 and C# is necessary while some knowledge about object oriented design certainly helps.

Part one dealt with the design of the application: what business objects do you need to fulfill the requirements of the application. What should these objects be capable of and how do they look. How do these business objects interact with other parts of the system? Part two showed you how to code the classes that were designed in part one. You saw how to implement the data access methods and database code and how the various classes were able to work together. You also saw how to use the API to programmatically create contact persons and their contact data and save those in a database. However, writing explicit code to work with your business objects isn't always fun, and can be a cumbersome task.

Therefore, this article (part three) deals with using the business objects in a web application. You'll see how to use the ASP.NET controls like the GridView in conjunction with the business objects. You'll see how you can build pages that allow you to list, create, edit and delete your contact persons and their contact data, like e-mail addresses and phone numbers.

If you haven't read part one or two yet, you should really read them first, as this article uses many concepts that have been explained in part one and two. The entire series (including this current article) can be found here:

• Building Layered Web Applications with Microsoft ASP.NET 2.0 - Part 1
• Building Layered Web Applications with Microsoft ASP.NET 2.0 - Part 2
• Building Layered Web Applications with Microsoft ASP.NET 2.0 - Part 3

The article uses a SQL Server 2005 Express database which is easy to use in development scenarios. However, the downloads for this series also come with the T-SQL scripts to recreate the database in SQL Server 2000 or SQL Server 2005. You'll find the download link at the end of this article. Besides the forementioned SQL scripts and database, the download also contains the full source for the demo application in C#.

Update!! 02-27-2007 - I just got an e-mail from my team member Marcel who pointed me to this article: http://forums.asp.net/thread/1501276.aspx

Funny thing is, I was already using the code from that article to fix an issue with Ajax RC. Turns out that with the RTM release this code is no longer necessary, and additionally, now seems to crash FireFox when using Firebug. I removed the offending JavaScript and everything is fine now. Thank you Marcel!!

If you still have issues browsing this site with Firefox, please let me know.

Over the past couple of weeks, I received a number of e-mails from people reporting that their FireFox browser crashed when browsing my site.