Custom page classes involve creating a class that inherits
from System.Web.UI.Page. For instance, the class below is a custom page class.
public class MyCustomPageClass : System.Web.UI.Page
MyCustomPageClass is a custom page class in this case
because it inherits from Page. The benefit to this is that it can provide added
features to all of the pages that inherit from it. There are other benefits as
well, as described in this article.
One of the benefits that this article will discuss is the ability to have pages
and user controls communicate with each other. The problem with the web site
model is that the code-behind page is dynamically compiled in the assembly and
is cut off from user controls that it may use.
The custom class can exist in the App_Code and can work
uncompiled, be in a separate class project, or precompiled in the bin folder,
using the publish web site option.