gtk-sharpGtk# is thread aware, but not thread safe; See the Gtk# Thread Programming for details.GLib.SignalArgsEvent data.The event invokes delegates which pass event data via this class.'s RetVal is a boolean.To keep a from closing, set 's .RetVal to true.ConstructorPublic Constructor.Create a new instance with this constructor if you need to invoke a delegate.PropertyGdk.EventThe event that triggered this window's deletion.a