Programming Microsoft® ASP.NET 4

Chapter 4. HTTP Handlers, Modules, and Routing

Advice is what we ask for when we already know the answer but wish we didn’t.

— Erica Jong

HTTP handlers and modules are truly the building blocks of the ASP.NET platform. Any requests for a resource managed by ASP.NET are always resolved by an HTTP handler and pass through a pipeline of HTTP modules. After the handler has processed the request, the request flows back through the pipeline of HTTP modules and is finally transformed into markup for the caller.

The Page class—the base class for all ASP.NET runtime pages—is ultimately an HTTP handler that implements internally the page life cycle that fires the well-known set of page events, including postbacks, Init, Load, PreRender, and the like. An HTTP ...