I'm working with some WebForms/MVC-agnostic tools, and I need to get an instance of HttpContext
given a reference to an HttpContextBase
object. I can't use HttpContext.Current
because I need this to work asynchronously as well (HttpContext.Current
returns null
during an asynchronous request). I'm aware of HttpContextWrapper
, but goes the wrong way.
The simplest way is to get the application, ApplicationInstance
, and use its Context
property:
// httpContextBase is of type HttpContextBase
HttpContext context = httpContextBase.ApplicationInstance.Context;
(thanks to Ishmael Smyrnow who noted this in the comments)
You can, especially if the HttpContextBase
instance you've been handed is of type HttpContextWrapper
at run-time. The following example illustrates how you can do this. It supposes you have a method called Foo
that accepts context as HttpContextBase
but then needs to call a method in a third-party assembly (that you may not have the good fortune to modify) that is expecting the context to be typed as HttpContext
.
void Foo(HttpContextBase context)
{
var app = (HttpApplication) context.GetService(typeof(HttpApplication));
ThirdParty.Bar.Baz(app.Context);
}
// Somewhere in assembly and namespace ThirdParty,
// in a class called Bar, there is Baz expecting HttpContext:
static void Baz(HttpContext context) { /* ... */ }
HttpContextBase
has a method called GetService
as a result of supporting IServiceProvider
. The GetService
override of HttpContextWrapper
delegates to the GetService
implementation of the wrapped HttpContext
instance. The GetService
implementation of HttpContext
allows you to query for usual suspects like HttpApplication
, HttpRequest
, HttpResponse
and so on. It just so happens that HttpApplication
has a property called Context and which returns an instance of HttpContext
. So one gets at the wrapped HttpContext
instance by asking HttpContextBase
for HttpApplication
via GetService
followed by reading the Context
property of the returned HttpApplication
instance.
Unlike HttpContextBase
, GetService
does not appear as a public member of HttpContext
but that is because HttpContext
implements IServiceProvider.GetService
explicity while HttpContextBase
doesn't.
Bear in mind that Foo
is no longer testable because it relies on being able to unwrap the underlying HttpContext
during testing and which is next to impossible to fake/stub in the first place. The point of this answer, however, is to address the question, “How do I get an HttpContext object from HttpContextBase?”, literally. The illustrated technique is useful in those situations where you find yourself sandwiched between components you don't necessarily have the luxury to modify.