//单例,保持内存唯一实例
 public static EventAggregatorRepository GetInstance()
 {
     if (eventRepository == null)
     {
         eventRepository = new EventAggregatorRepository();
     }
     return(eventRepository);
 }
        public void UseCode()
        {
            EventAggregatorRepository
            .GetInstance()
            .eventAggregator
            .GetEvent <MessageSentEvent>().Publish("");

            EventAggregatorRepository
            .GetInstance()
            .eventAggregator
            .GetEvent <MessageSentEvent>()
            .Subscribe(ProgressValueChanged, ThreadOption.UIThread, true);
        }