Beware the perils of the VS2005 Development Web Server

One of the slick new features of Visual Studio 2005 is the ASP.NET Development Web Server - basically a scaled down web server that you can use during web application development instead of using IIS. I've been using it for a while, and it generally worked great. However,  I recently tried to deploy my web app to an IIS server, and it suddenly stopped working. It turns out that the behavior of one the 3rd party ASP.NET server controls I was using changed when I switched to IIS. In this case, it was a chart control that suddenly stopped rendering its images correctly.

I haven't yet figured out the fundamental problem (the control wasn't designed for .NET 2.0, so it could be a version issue). I'm not bashing the Development Web Server - it's a very handy feature. The moral of the story is that the DWS is not IIS - don't be lulled into believe that they are interchangeable.


2 Comments

  • Kevin,



    I've had a similar experience when enabling forms authentication on a web application. Turns out ASP.NET Development Server handles pages differently than IIS (a little) and will not render CSS or images during debug/non-debug viewing through VS.NET on pages that are not under forms authentication. Makes it so that you really don't get WYSIWYG during development.



    Developing the same app under IIS works perfectly. For now, I plan on continuing development against IIS. I love the ASP.NET Development Server (Cassini), but for now I am seeing some differences.



    JW

  • It's funny how every year or so I see people discovering things that I learned a long time ago. Specifically, I learned this lesson the hard way with PWS. I don't even remember which OS it was from anymore.

    Since then, unless I am doing very plain and simple code/html, I dev off a true IIS box. The job I'm at now has me working off of xp pro, and I'm just waiting for that production Gotcha! to come bite me again on some goofy little item....



    Dev against your true target whenever you can...

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