ASP.NET in a Nutshell

Chapter 14. The HttpContext Class

With all the knowledge gained about the HttpApplicationState class covered in the last chapter, the next question is, “How you gain access to a copy of the HttpApplicationState within your application?” The good news is that within an ASP.NET page, the Application instance of the HttpApplicationState class is available exactly as it appears in a classic ASP page. The Response, Request and other objects familiar to classic ASP are also available. These and other objects are available by using the HttpContext class.

Unlike many classes within ASP.NET, the HttpContext class adds new methods and properties but does not contain any significant methods or properties carried over from classic ASP that are deprecated in ASP.NET. New properties include IsCustomErrorEnabled, IsDebuggingEnabled, SkipAuthorization, and Trace.

The HttpContext class encapsulates all the HTTP-specific information about a given HTTP request. The HttpContext class contains an Items collection that allows the developer to store information for the duration of the current request. In some ways, this class is similar to HttpSessionState (discussed in Chapter 19). However, information stored in the HttpContext collection is held only for the duration of the current request. While this might not initially seem useful, it is often helpful.

For instance, suppose an application is structured so that the user enters information into a form and clicks a button with a server-side event handler. ...