gdk-sharp2.12.0.0Gtk# is thread aware, but not thread safe; See the Gtk# Thread Programming for details.Describes how existing data is combined with new data.None.System.EnumGLib.GType(typeof(Gdk.PropModeGType))FieldGdk.PropModeThe new data replaces the existing data.FieldGdk.PropModeThe new data is prepended to the existing data.FieldGdk.PropModeThe new data is appended to the existing data.