What is HttpHandler
HTTPHandlers are used by ASP.NET web application server to handle specific requests based on extensions. HTTPHandlers run as processes in response to a request made to the ASP.NET website. It is a class that implements the System.Web.IHttpHandler interface. Any class that implements the IHttpHandler interface can perform as a target for the incoming HTTP requests.
It is an extension based processor and responsible for fulfilling requests from a browser depending on file extensions. When HttpHandler receives any request from browser, it checks the extension to see if it can handle that request and performs some predefined steps to respond that request.
ASP.NET framework offers a few default HTTP handlers. The most common handler is an ASP.NET page handler that processes .aspx files. Following are some default Handlers:
How to implement HTTPHandler ?
Any class that implements the IHttpHandler interface can perform as a target for the incoming HTTP requests. The class should have a method ProcessRequest and a property called IsReusable.
C# Source Code
VB.Net Source Code
IsReusable property return either true or false in order to specify whether they can be reused and ProcessRequest is called to process http requests.