How to use ASP.NET Session State in an HttpHandler?

Question

I have an HttpHandler that is run on a client page (cross domain, not on our IIS server, etc) and when they click on our embedded link it fires off the Handler on our server

Answer 1

Have your HttpHandler implement the IRequiresSessionState interface. It will enable session state use. IRequiresSessionState can be found in the System.Web.SessionState namespace.