C# 通用发布事件类

我试图开发一个通用类来引发一个事件

在运行时，我不知道将出现什么实体，这就是为什么我决定将其设置为泛型。问题是，可以存在的每个类型都继承自基类

EntityBase

• 在这个类中，我返回（或者我想：p）具有正确类型的事件

  public class EntityModifiedEventFactory<TEntity> : IEntityModifiedEventFactory<TEntity> where TEntity : EntityBase
  {
      private readonly IEventAggregator eventAggregator;
  
      public EntityModifiedEventFactory(IEventAggregator eventAggregator)
        {
           ParameterChecker.IsNotNull(eventAggregator, "eventAggregator");
  
           this.eventAggregator = eventAggregator;
        }
  
      public EntityModifiedEvent<TEntity> Create()
        {
           return this.eventAggregator.GetEvent<EntityModifiedEvent<TEntity>>();
        }
  }
  

  ---

  我终于解决了这个问题。如果有人经历了像我这样的事情，这就是答案：

      private void OnNotifyAgentEntityChanged(object sender, EntityChangedEventArgs entityChangedEventArgs)
      {
          this.PublishEvent((TEntity)entityChangedEventArgs.Entity);
      }
  
      private void PublishEvent(TEntity entity)
      {
          object args = this.GetEventArgs(entity);
          object eventObject = this.GetEventObject(entity);
  
          MethodInfo publishMethod = eventObject.GetType().GetMethod("Publish");
          publishMethod.Invoke(eventObject, new[] { args });
      }
  
      private object GetEventArgs(TEntity entity)
      {
          Type viewModelIdentifierEventArgsType = typeof(ViewModelIdentifierEventArgs<>).MakeGenericType(entity.GetType());
          object args = Activator.CreateInstance(viewModelIdentifierEventArgsType, Guid.NewGuid(), entity);
  
          return args;
      }
  
      private object GetEventObject(TEntity entity)
      {
          MethodInfo getEventMethod = typeof(IEventAggregator).GetMethod("GetEvent");
          Type entityModifiedEventType = typeof(EntityModifiedEvent<>).MakeGenericType(entity.GetType());
          MethodInfo genericGetEventMethod = getEventMethod.MakeGenericMethod(entityModifiedEventType);
          object eventObject = genericGetEventMethod.Invoke(this.eventAggregator, null);
  
          return eventObject;
      }
  

  NotifyAgentEntityChanged上的私有void（对象发送方，EntityChangedEventArgs EntityChangedEventArgs）
  {
  this.PublishEvent（（tenty）entityChangedEventArgs.Entity）；
  }
  私有事件（TEntity实体）
  {
  对象args=this.GetEventArgs（实体）；
  object eventObject=this.GetEventObject（实体）；
  MethodInfo publishMethod=eventObject.GetType（）.GetMethod（“发布”）；
  Invoke（eventObject，new[]{args}）；
  }
  私有对象GetEventArgs（TEntity实体）
  {
  类型ViewModelIdentifierEventTargetType=typeof（ViewModelIdentifierEventTargets）.MakeGenericType（entity.GetType（））；
  对象args=Activator.CreateInstance（ViewModelIdentifierEventTargetType，Guid.NewGuid（），实体）；
  返回args；
  }
  私有对象GetEventObject（TEntity实体）
  {
  MethodInfo getEventMethod=typeof（IEventAggregator）.GetMethod（“GetEvent”）；
  Type entityModifiedEventType=typeof（EntityModifiedEvent）.MakeGenericType（entity.GetType（））；
  MethodInfo genericGetEventMethod=getEventMethod.MakeGenericMethod（entityModifiedEventType）；
  object eventObject=genericGetEventMethod.Invoke（this.eventAggregator，null）；
  返回事件对象；
  }
  

  ---

  通过这样做，我可以发布任何

  EntityModifiedEvent

  ，而不考虑

  tenty

  。我只需要在我的

  EntityChangedEventArgs

  中添加

  KnownType

  ，这样就可以对其进行des/serialized
  编译器无法推断运行时提供的类型。您能否提供在哪里调用NotifyAgentEntityChanged方法？你能不能简单地用正确的entit ytype使EntityChangedEventArgs也通用？@HimBromBeere

  OnNotifyAgentityChanged

  它被一个WCF服务调用，在这里发布它会非常巨大

  OnNotifyAgentEntityChanged

  将事件发布给已订阅的人，如果订阅者是

  树

  或

  动物

  ，则会有所不同。发布此

  EntityModifiedEvent

  和发布此

  EntityModifiedEvent

  并不相同，即使它们继承自

  EntityBase

  。明确地说，我的问题是如何（如果可能的话）覆盖

  EntityModifiedEventFactory

  的泛型类型。

          ViewModelIdentifierEventArgs<Tree> eventArgs = new ViewModelIdentifierEventArgs<Tree>(entityChangedEventArgs.ViewModelIdentifier, (Tree)entityChangedEventArgs.Entity);
  
          IEntityModifiedEventFactory<Tree> entityModifiedEventFactory = new EntityModifiedEventFactory<Tree> ((Tree)entityChangedEventArgs.Entity, this.eventAggregator);
          EntityModifiedEvent<Tree> entityModifiedEvent = entityModifiedEventFactory.Create();
  
          entityModifiedEvent.Publish(eventArgs);
  

      private void OnNotifyAgentEntityChanged(object sender, EntityChangedEventArgs entityChangedEventArgs)
      {
          this.PublishEvent((TEntity)entityChangedEventArgs.Entity);
      }
  
      private void PublishEvent(TEntity entity)
      {
          object args = this.GetEventArgs(entity);
          object eventObject = this.GetEventObject(entity);
  
          MethodInfo publishMethod = eventObject.GetType().GetMethod("Publish");
          publishMethod.Invoke(eventObject, new[] { args });
      }
  
      private object GetEventArgs(TEntity entity)
      {
          Type viewModelIdentifierEventArgsType = typeof(ViewModelIdentifierEventArgs<>).MakeGenericType(entity.GetType());
          object args = Activator.CreateInstance(viewModelIdentifierEventArgsType, Guid.NewGuid(), entity);
  
          return args;
      }
  
      private object GetEventObject(TEntity entity)
      {
          MethodInfo getEventMethod = typeof(IEventAggregator).GetMethod("GetEvent");
          Type entityModifiedEventType = typeof(EntityModifiedEvent<>).MakeGenericType(entity.GetType());
          MethodInfo genericGetEventMethod = getEventMethod.MakeGenericMethod(entityModifiedEventType);
          object eventObject = genericGetEventMethod.Invoke(this.eventAggregator, null);
  
          return eventObject;
      }