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

Question

Dear ladies and sirs.

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

You can check for

HttpContext.Current

If it is not null then it is run from a web app.

See HttpContext.Current Property

Answer 2

• BrowserInteropHelper..::.IsBrowserHosted Property

Gets a value that specifies whether the current Windows Presentation Foundation (WPF) application is browser hosted.

Thats how its done in XBAP

• Performing Browser Detection Using ASP.NET

or if you have an appdomain do reflection and get something from it? using

• Reflection CallContext

Answer 3

You can Find out the current process name:

Process p = Process.GetCurrentProcess();
string assemblyName = p.ProcessName;

and then check if this is the ASP.NET process name

Answer 4

The best option is a config setting.

It's better for testability; it's better because it's an obvious statement of how the code will work, and it's better because it doesn't rely on implementation details; you specifically branch from a value you set. It may be that the decision you are making is non-obvious and your variable/config can be suggestive of the reasoning.

It's the option I'd go for.

Answer 5

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.

Answer 6

I think the very best thing to do is to split up the library into 2 dlls, one that's truly generic, and one (the one that requires ASP.NET) that only gets loaded in the website. Checking if it's currently running in ASP.NET feels like a bit of a hack.

Ofcourse it depends on the situation wether or not you can easily do this.