Question

I will appreciate any help on steps for an implementation to switch an MVC3/Razor Web Application to offline mode for maintenance. At the offline mode only a static page could be seen by the public but an administrator who is logged in should be able to view, browse and update the site fully. Ideally I want the web administrator just to tick on a value at the administrative back-end which will be registered in the database.

Answer 1

You could simply check some condition within BeginRequest in Global.asax.

protected void Application_BeginRequest()
{
    if (myDb.SiteIsOffline && !CurrentUserIsAdministrator())
        Response.Redirect("~/offline.html");
}