protected override void OnAttached()
{
var triggers = Interaction_
.GetTriggers(AssociatedObject)
.OfType <EventTrigger>();
var actions = triggers
.First(t => t.EventName == "Closing")
.Actions
.OfType <InvokeCommandAction>();
_commandAction = actions.First();
AssociatedObject.Closing += _windowClosingHandler;
}
