Assembly: System.Web (in system.web.dll)
An IHttpAsyncHandler class can be associated with a file name extension or a particular URL by a configuration file, in the httpHandlers configuration section. The ASP.NET infrastructure will then instantiate and call the handler when the corresponding request is received. Alternatively, the handler can be defined in an .ashx file and when the corresponding request is received for the .ashx file the hander will be executed.
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.