Question

所以我有一个创建汽车演员的演员，我将新车添加到地图中，并且我需要从地图上向它发送已损坏的消息，我该怎么做？

    var cars = Map.empty[String, ActorRef]
   override def receive: Receive = {
   case CreateTank(id) =>
    val newTank = context.actorOf(Car.props(id,hp=100), s"tank-$id")
    cars = cars + (id -> newCar)
    sender() ! CarCreated(id)

   case CarDestroyed(id) =>
    val thisCar = cars.get(id)
    thisCar ! CarDestroyed
   }

Answer 1

在get上调用Map返回Option，因此一种方法是在查找结果上调用foreach：

var cars = Map.empty[String, ActorRef]

def receive = {
  case CreateCar(id) =>
    val newCar = context.actorOf(Car.props(id, hp=100), s"car-$id")
    cars = cars + (id -> newCar)
    sender() ! CarCreated(id)

  case CarDestroyed(id) =>
    cars.get(id).foreach(_ ! CarDestroyed)
}

上述参与者在收到CarDestroyed消息时，会向与id关联的参与者发送CarDestroyed消息（如果存在）。

此外，我可以随意调整其他case子句，因为看来您将汽车的创建与坦克的创建混淆了。

Answer 2

jeffrey是完全正确的。在地图上获取该选项，作为回报，您可以执行以下操作：

var cars = Map.empty[String, ActorRef]
   override def receive: Receive = {
   case CreateTank(id) =>
    val newTank = context.actorOf(Car.props(id,hp=100), s"tank-$id")
    cars = cars + (id -> newCar) /* i think this should be newTank becaue 
it has the actor ref for the new Car actor */
    sender() ! TankCreated(id)

   case CarDestroyed(id) =>
    val thisCar = cars.get(id)
if(thisCar.isDefined)
    thisCar.get ! CarDestroyed
   }

如何从地图获取演员参考

2 个答案: