Chapter 3 Anatomy of an ASP.NET Page

Overview

ASP.NET pages are dynamically compiled on demand when first required in the context of a Web application. Dynamic compilation is not specific to ASP.NET pages alone (.aspx files); it also occurs with .NET Web Services (.asmx files), Web user controls (.ascx files), HTTP handlers (.ashx files), and a few more ASP.NET application files such as the global.asax file. A pipeline of run-time modules takes care of the incoming HTTP packet and makes it evolve from a simple protocol-specific payload up to the rank of a server-side ASP.NET object precisely, an instance of a class derived from the system's Page class. The ASP.NET HTTP runtime processes the page object and causes it to generate the markup to insert in the response. The generation of the response is marked by several events handled by user code and collectively known as the page life cycle.

In this chapter, we'll review how an HTTP request for an .aspx resource is mapped to a page object, the programming interface of the Page class, and how to control the generation of the markup by handling events of the page life cycle.