When I checked more thoroughly, I realized that the problem is actually that the FileChooserDialog.Filenames is empty, as is FileChooserDialog.Filename, even after the user selects a file(s). -- View this message in context: http://mono.1490590.n4.nabble.com/Treeview-problem-tp2316287p2318623.html Sent from the Mono - Gtk# mailing list archive at Nabble.com.