Request.GetOwinContext()打不到
Although it's in the Microsoft.Owin.Host.SystemWeb assembly it is an extension method in the System.Web namespace, so you need to have the reference to the former, and be using the latter.
Although it's in the Microsoft.Owin.Host.SystemWeb assembly it is an extension method in the System.Web namespace, so you need to have the reference to the former, and be using the latter.