How can a .NET code know whether it is running within a web server application?

Question

I have a library code, which should be aware whether it is executed in the context of a web server or standalone application server.

The obvious that comes to mind is to check the name of the application configuration file and if it is web.config - then this is a web server, otherwise - standalone application server.

Another way is to look for something like "Temporary ASP.NET files" in the path of the shadow folder.

But I dislike both of these, since they seem too hacky and fragile. Is there a robust way to do what I want?

Thanks.

P.S.

One may define a dedicated app config setting - IsWebServer, but I dislike it even more.

EDIT:

While looking for a solution to another problem, I think I solved this one - the details are here

Answer 1

Trying to solve another problem, I found a good solution for this one. There is a private method System.Configuration.SettingsPropertyValue.IsHostedInAspnet, which does exactly what I need. Being a private method, I do not want to call it (though I could using reflection), but its implementation is trivial:

private bool IsHostedInAspnet()
{
    return (AppDomain.CurrentDomain.GetData(".appDomain") != null);
}

(according to Reflector)

Looks like there is a special key in the app domain data - ".appDomain", which is set when running in ASP.NET web server.

I will stick to that.