Opening site collection with admin user to prevent access exceptions

Question

I have a custom webservice hosted in SharePoint. Within this service, I need to at times look up sites by id. Despite running code in an SPSecurity.RunWithElevatedPriviledges block, I still get Access exceptions for non-admin users when trying to look up a site by id.

From what I've read, I may be able to get around this problem by opening the site collection using a User token for an admin account. My problem is, how do I get a user token for an admin account?

Any help is greatly appreciated.

Example:

//Putting this inside RunWithElevatedPrivileges causes it to fail
var siteCollection = new SPSite(SITE_COLLECTION_URL);

SPSecurity.RunWithElevatedPrivileges(() =>
{
    //This throws for non-admins, regardless of being in a RunWithElevatedPriviledges block
    var web = siteCollection.AllWebs[webId]); 
}

Answer 1

In order to properly use RunWithElevatedPrivileges(), you need to move the new SPSite() call inside the elevated block. otherwise it will get the SPSite reference using the ID of the user instead of the App Pool ID.

from Microsoft: "An SPSite object created outside the delegate can be referenced inside the delegate, however, the methods and property assessors of the object run with the privileges of the user context in which the objects were created, not with the elevated privileges."