ASP.NET Request Processing
ASP.NET maps HTTP requests to HttpHandlers. Each HttpHandler enables processing of individual HTTP URLs or groups of URL extensions within an application. HttpHandlers have the same functionality as ISAPI extensions with a much simpler programming model. The following table shows examples of the HttpHandlers provided by ASP.NET.
|ASP.NET Page Handler (*.aspx)||The default HttpHandler for all ASP.NET pages.|
|ASP.NET Service Handler (*.asmx)||The default HttpHandler for all ASP.NET service pages.|
An HttpHandler can be either synchronous or asynchronous. A synchronous handler does not return until it finishes processing the HTTP request for which it is called. An asynchronous handler usually launches a process that can be lengthy, and returns before that process finishes.
After writing and compiling the code to implement an HttpHandler, you must register the handler using your application's Web.config file.