A custom HTTP handler can be created by implementing the IHttpHandler interface, which contains only two methods. By calling IsReusable , an HTTP factory can query a handler to determine whether the same instance can be used to service multiple requests. The ProcessRequest method takes an HttpContext instance as a parameter, which gives it access to the Request and Response intrinsics. In the following sample, request data is ignored and a constant string is sent as a response to the client. Section Summary HTTP Handlers and factories are the backbone of the ASP.NET page framework.
Factories assign each request to one handler, which processes the request.
Factories and handlers are defined in the web.config file. Settings for factories are inherited by subdirectories.