Add custom menu actions programmatically in SharePoint 2010
using ( SPSite site = new SPSite ( "http://moss.dev.com" )) { using ( SPWeb web = site . OpenWeb ()) { SPContentType contentType = web . ContentTypes [ "Curriculum Vitae" ]; SPUserCustomAction action = web . UserCustomActions . Add (); action . RegistrationType = SPUserCustomActionRegistrationType . ContentType ; action . RegistrationId = contentType . Id . ToString (); action . Location = "EditControlBlock" ; action . Sequence = 450 ; action . Title = "Test" ; action . Rights = SPBasePermissions . EditListItems ; action . Url...