Does App_Code in ASP.Net compile new code to a secondary temp AppDomain?

Question

I am trying to better understand how the App-Code folder operates, and in particular I am curious how new objects that a new class in the App-Code folder are included in the current AppDomain. Is a second, temporary AppDomain created in the same manner as when I compile new objects with the CodeDom?

In many ways the capability of moving new classes / objects into a Web Application is very compelling. Rob Connery's MVC Storefront is a good illustration. If you have used the App-code folder to deploy new functionality were there any trade-offs or gotchas that should be considered?

UPDATE:

I found an article in CoDe Magazine with this interesting passage:

Your application-specific code can go inline of the ASPX page or control, it can go into a CodeBeside partial class, or you can create completely autonomous classes in the APP_CODE folder. The APP_CODE folder is a special folder in an ASP.NET 2.0 project and any non-page or control-related source code in your Web project must go into this folder. ASP.NET treats the content of APP_CODE like a library project and compiles the content into a separate assembly. This assembly is then referenced by all of the page or directory-level assemblies that ASP.NET creates from your ASPX/ASCX pages that use any of the classes defined in APP_CODE.

My question still stands - is a second AppDomain created that supports this libary, and if so are the impacts on performance minimal?

Answer 1

I don't know the details, but it will certainly be in different dynamic assemblies. A class can't be in another AppDomain. Only an instance of a class can be in another AppDomain, and then it's really a hassle to access from another AppDomain (only through remoting)