Event Receiver

https://social.msdn.microsoft.com/Forums/sqlserver/en-US/403c001b-b720-4b12-bb5c-6b95c9fbaf89/how-to-get-column-values-on-item-added-event-receiver?forum=sharepointdevelopmentprevious



https://www.red-gate.com/simple-talk/dotnet/net-tools/managing-itemupdating-and-itemupdated-events-firing-twice-in-a-sharepoint-item-event-receiver/


https://docs.microsoft.com/en-us/previous-versions/office/developer/sharepoint-2010/ff521580(v%3Doffice.14)


https://sharepoint.stackexchange.com/questions/216386/add-new-itemeventreceiver-methods-in-visual-studio-on-top-of-existing-event-rece


https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/handle-list-item-events-in-the-provider-hosted-add-in

using (SPSite originalsite = new SPSite(properties.SiteId, properties.OriginatingUserToken))
{
  //To get the current user
  using (SPWeb web = originalsite.OpenWeb())
  {
    string strUserName = web.CurrentUser.LoginName.ToString();
  }
}