如何在 Ninject 中设置依赖注入？

Question

我正在尝试使用 Akka .NET 设置依赖注入。在关于该主题的 Pluralsight 课程之后，我提出了以下改编：

        var container = new StandardKernel();
        container.Bind<ITimeService>().To<LocalTimeService>();
        container.Bind<TimeLordActor>().ToSelf();

        using (var actorSystem = ActorSystem.Create("MyActorSystem"))
        {
            var resolver = new NinjectDependencyResolver(container, actorSystem);

            var actor = actorSystem.ActorOf(Props.Create<TimeLordActor>(),
                "TimeLordActor");
            actor.Tell("Give me the time!");

            Console.WriteLine("Press ENTER to exit...");
            Console.ReadLine();
        }

TimeLordActor 的构造函数需要ITimeService 类型的参数。

但是，运行时出现以下错误：

[ERROR][7/10/2016 5:39:42 PM][Thread 0012][akka://MyActorSystem/user/TimeLordActor] Error while creating actor instance of type AkkaNetDiExperimental.TimeLordActor with 0 args: () Cause: [akka://MyActorSystem/user/TimeLordActor#1586418697]: Akka.Actor.ActorInitializationException: Exception during creation ---> System.TypeLoadException: Error while creating actor instance of type AkkaNetDiExperimental.TimeLordActor with 0 args: () ---> System.MissingMethodException: Constructor on type 'AkkaNetDiExperimental.TimeLordActor' not found. at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, StackCrawlMark& stackMark) at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) at System.Activator.CreateInstance(Type type, Object[] args) at Akka.Actor.Props.ActivatorProducer.Produce() at Akka.Actor.Props.NewActor() --- End of inner exception stack trace --- at Akka.Actor.Props.NewActor() at Akka.Actor.ActorCell.CreateNewActorInstance() at Akka.Actor.ActorCell.<>c__DisplayClass118_0.<NewActor>b__0() at Akka.Actor.ActorCell.UseThreadContext(Action action) at Akka.Actor.ActorCell.NewActor() at Akka.Actor.ActorCell.Create(Exception failure) --- End of inner exception stack trace --- at Akka.Actor.ActorCell.Create(Exception failure) at Akka.Actor.ActorCell.SysMsgInvokeAll(EarliestFirstSystemMessageList messages, Int32 currentState)

Akka .NET Dependency Injection 上的官方文档建议在直接创建 Actor 时应该在 ActorSystem 实例上使用 DI() 扩展方法：

// Create the Props using the DI extension on your ActorSystem instance
var worker1Ref = system.ActorOf(system.DI().Props<TypedWorker>(), "Worker1");
var worker2Ref = system.ActorOf(system.DI().Props<TypedWorker>(), "Worker2");

但是，我什至在actor系统上都找不到这个扩展方法。

谁能解释一下如何使用actor系统本身的依赖注入来创建一个简单的actor？

Answer 1

我想通了。您必须按照文档的建议使用 DI() 扩展方法。这是在Akka.DI.Core 命名空间中。

using Akka.DI.Core;

然后记得更新actor创建以反映文档使用的方法：

var actor = actorSystem.ActorOf(actorSystem.DI().Props<TimeLordActor>(),
                "TimeLordActor");