Defines the contract that HTTP asynchronous handler objects must implement.
Assembly: System.Web (in System.Web.dll)
An 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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.