Missing HttpContext

I've got a project which as a reference added to System.Web.

However, it can't seem to pick up HttpContext. Doing this:

Imports System.Web
_ApplicationBase = HttpContext.Current()

Tells me that HttpContext is not declared. If you look at the methods and properties inside System.Web there are hardly any showing: only AspHostingPermission, AspHostingPermissionAttribute, AspHostingPermissionLevel and Services.

The reference is valid and pointing to the right place. This is driving me crazy开发者_StackOverflow社区 - what have I missed?

Cheers, Matt

---

If this error is happening at design time then it's a case of a missing assembly reference. Make sure your project is referencing the System.Web.dll assembly.

---

An HttpContext object exists only during an asp.net request on the thread that is processing the request. In any other thread or process, there is no HttpContext available.