In an ItemAdded event receiver, is there a way to ascertain whether the file was uploaded via the "new item" button in the document library or whether it was dragged and dropped into the browser window?
In 2013 there are only 3 way to upload document in library. 1) Using New Item link. 2) Via drag and drop. 3) Open library using Window explorer.
Note:- Link to upload multiple item in library was removed in SharePoint 2013.