Q:

HttpHandler on a file in ASP.NET MVC

I have a following setup. I have a web application and in the .css of this application I define a background image to be presented when I hover over some element.
I want a script or something of that sort that sits on the server and when the image is accessed, it calls an action on the application. Unfortunately, I have no idea where to begin.
I want to know if and some hints on how to write a server side component that executes an action in web application based on the request for a file by css.
I am on Windows7, ASP.NET MVC.
EDIT
So, I have followed your suggestions on using httpHandlers. It seems like the perfect solution. However, I am running into problems.
I have followed this very helpful link http://www.phpvs.net/2009/08/06/aspnet-mvc-how-to-route-to-images-or-other-file-types/ but I was just unable to get a hit on a route
routes.Add("ImageRouting", new Route("Content/themes/base/images/{filename}.png", new ImageRouteHandler()));

My only other route is the one generated by default by MVC template.
So I figured out that the requests to a file are not handled by default by MVC. So I had to fix that by by setting the RouteExistingFiles property of the RouteCollection to true. 
Now I get proper hits on my images but for some reason, Site.css located in Content folder is not used to style the resulting html.
Any suggestions?

A:

Add an HttpHandler in your machine.config or web.config like so:
<httpHandlers>
    <add verb="supported http verbs" path="path" type="namespace.classname, assemblyname" />
<httpHandlers>

Your verb can be "*" or "GET", set path equal to the location of your image file on the server, and fill the type variables according to your namespace, class and handler function.
For a more detailed explanation, see:
http://www.15seconds.com/issue/020417.htm

