HttpContext.Current.Session is null

Question

I'm loading a page with WebPart in it, and I get NullReferenceException in this line:

HttpContext.Current.Session["Foo"] = value;

because Session is null. The web.config under inetpub folder has

<pages enableSessionState="false" ... >

Does session bag being null is caused by this setting in web.config, or is the cause completely different?

Answer 1

Yes, If you want to use the session-state, you should enable it in the web.config of the webapplication.

To enable ASP.NET session state:

1. Enter the following PowerShell command in the SharePoint 2010 Management Shell window: Enable-SPSessionStateService –DefaultProvision
   or more advanced:
   Enable-SPSessionStateService -DatabaseName [-DatabaseServer ] [-DatabaseCredentials ]
2. On each web application for which you want to use session state, edit the web.config file and set the enableSessionState property of the pages element as follows:
   < pages enableSessionState="true"

Answer 2

To use session state in SharePoint see Using Session State in SharePoint 2010, but think hard about if you really want to do it.