Console Application

Create Message Class Greet

The way to tell an actor to do something is by sending it a message. Greet is the message type to be sent!

namespace HelloWorld
{
    /// <summary>
    /// Immutable message type that actor will respond to
    /// </summary>
    public class Greet
    {
        public string Who { get; private set; }

        public Greet(string who)
        {
            Who = who;
        }
    }
}

Creating the GreetingActor

using Akka.Actor;

namespace HelloWorld
{
    /// <summary>
    /// The actor class
    /// </summary>
    public class GreetingActor : ReceiveActor
    {
        public GreetingActor()
        {
            // Tell the actor to respond to the Greet message
            Receive<Greet>(greet => Console.WriteLine($"Hello {greet.Who}"));
        }
        protected override void PreStart()
        {
            Console.ForegroundColor = ConsoleColor.Green;
            Console.WriteLine("Good Morning, we are awake!");
        }

        protected override void PostStop()
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("Good Night, going to bed!");
        }
    }
}

PreStart will be called by the Akka framework when the actor is getting started. The PostStop will be called after the actor is stopped.

Creating a Console Host

ActorSystem system = ActorSystem.Create("the-universe");

// create actor and get a reference to it.
// this will be an "ActorRef", which is not a 
// reference to the actual actor instance
// but rather a client or proxy to it
IActorRef greeter = system.ActorOf<GreetingActor>("greeter");

// send a message to the actor
greeter.Tell(new Greet("World"));

// give the actor a moment to process the message
// (it should process it in under a micro-second, but it happens asynchronously)
await Task.Delay(TimeSpan.FromSeconds(1));
system.Stop(greeter);

await system.Terminate();