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我正在研究使用域事件从发生在我的域模型深处的操作中提取信息，以便在控制器级别发出某些事件的信号。不幸的是，我无法找到如何在 asp.net mvc 控制器上正确连接它的示例。

简而言之，这就是我在行动中寻找的内容：

service.doSomethingComplicated();
var model = new ViewModel();
model.somethingComplicatedCausedSomethingElse = <true-if-my-domain-event-was-raised>;
return View(model);

谁能给我一些指导？

更新

为了清楚起见，我了解如何在控制器中引发和处理域事件；我只是在寻找一种在我所描述的上下文中可以安全使用的事件注册实现。

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1 回答 1

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根据您链接到的示例，作者这样做：

Customer preferred = null;

DomainEvents.Register<CustomerBecamePreferred>(
    p => preferred = p.Customer
        );

c.DoSomething();

你应该能够做到这一点：

    var model = new ViewModel();

    // Register a handler that sets your bool to true if / when the event is raised
    DomainEvents.Register<YourDomainEvent>(e => model.somethingComplicatedCausedSomethingElse = true);
    // EDIT: If using the singleUseActions modification, pass the second parameter
    // DomainEvents.Register<YourDomainEvent>(e => model.somethingComplicatedCausedSomethingElse = true, true);

    // Call the service. If it raises the event, the handler you just registered will set your bool
    service.doSomethingComplicated();

    return View(model);

编辑（DomainEvents 修改） 这是未经测试的，并在 StackOverflow 编辑框中编写，但这是我要开始的地方。我正在使用一个可选参数，以便不需要修改现有调用，并使用一个单独的列表“singleUseActions”来尽可能保持现有的胆量不变。希望能帮助到你。

public static class DomainEvents
  { 
      [ThreadStatic] //so that each thread has its own callbacks
      private static List<Delegate> actions;

      [ThreadStatic] //so that each thread has its own callbacks
      private static List<Delegate> singleUseActions;

      public static IContainer Container { get; set; } //as before

      //Registers a callback for the given domain event
      public static void Register<T>(Action<T> callback, bool isSingleUse = false) where T : IDomainEvent
      {
         List<Delegate> targetList;
         if (isSingleUse)
         {
             if (singleUseActions == null) singleUseActions = new List<Delegate>();
             targetList = singleUseActions;
         }
         else
         {
             if (actions == null) actions = new List<Delegate>();
             targetList = actions;
         }

         targetList.Add(callback);
     }

     //Clears callbacks passed to Register on the current thread
     public static void ClearCallbacks ()
     {
         actions = null;
         singleUseActions = null;
     }

     //Raises the given domain event
     public static void Raise<T>(T args) where T : IDomainEvent
     {
        if (Container != null)
           foreach(var handler in Container.ResolveAll<Handles<T>>())
              handler.Handle(args);

        if (actions != null)
            foreach (var action in actions)
                if (action is Action<T>)
                    ((Action<T>)action)(args);

        if (singleUseActions != null)
            // Don't foreach because we are going to modify the collection
            for (int index = singleUseActions.Count - 1; index > -1; index--)
            {
                var singleUseAction = singleUseActions[index];
                if (singleUseAction is Action<T>)
                {
                    ((Action<T>)singleUseAction)(args);
                    singleUseActions.RemoveAt(index);
                }
            }


  }
}
于 2011-04-13T17:17:54.117 回答