Autofac，MediatR&多个DLL项目

问题描述

我有几个(最终超过100个)小型DLL项目，这些项目均基于MediatR.这意味着正在使用的接口只是IMediatR接口( IRequest< TResult>，IRequestHandler< IRequest< TResult>，TResult> ).由于其中许多没有UI，并且通过另一个DLL的编排调用，因此我想我可以创建一个Autofac容器项目(DLL)，注册所有微服务，然后在运行时在另一个应用程序中解决我需要的内容，消耗我的容器.到目前为止，一切都很好.

I have several (eventually 100+) small DLL projects all based on MediatR. This means that the interfaces in use are just the IMediatR interfaces (IRequest<TResult>, IRequestHandler<IRequest<TResult>, TResult>). Since a lot of these do not have a UI and are called via orchestration from another DLL I was thinking I could create an Autofac Container project (DLL), register all the micro-services, then resolve what I need at runtime in another app that consumes my container. So far, so good.

我遇到问题的地方是每个CQRS处理程序的注册.现在，尽管所有内容都很小，但它们是按以下方式内联定义的:

Where I am running into problems is the registration of each and every CQRS handler. Right now, while everything is small in scope, they are being defined inline like this:

namespace My.Core.Container
{
    public class CoreDependencies
    {
        #region Properties
        public IMediator Mediator { get; private set; }
        public IContainer Container { get; private set; }

        private static ContainerBuilder _builder;
        #endregion

        #region Constructor
        public CoreDependencies()
        {
            _builder = new ContainerBuilder();

            // register MediatR types...
            _builder.RegisterSource(new ContravariantRegistrationSource());
            _builder.RegisterAssemblyTypes(typeof(IMediator).GetTypeInfo().Assembly).AsImplementedInterfaces();
            _builder.Register<SingleInstanceFactory>(ctx => 
            {
                var c = ctx.Resolve<IComponentContext>();
                return t => c.Resolve(t);
            });
            _builder.Register<MultiInstanceFactory>(ctx =>
            {
                var c = ctx.Resolve<IComponentContext>();
                return t => (IEnumerable<object>)c.Resolve(typeof(IEnumerable<>).MakeGenericType(t));
            });

            // ################################################## //
            // register EntityTree micro services...
            _builder.RegisterAssemblyTypes(typeof(My.Core.EntityTree.GetChildren).GetTypeInfo().Assembly).AsImplementedInterfaces();
            _builder.RegisterAssemblyTypes(typeof(My.Core.EntityTree.DeleteEntity).GetTypeInfo().Assembly).AsImplementedInterfaces();
            _builder.RegisterAssemblyTypes(typeof(My.Core.EntityTree.AddEntity).GetTypeInfo().Assembly).AsImplementedInterfaces();

            // register next micro services...
            // register next micro services...
            // ad naseum...
            // ################################################## //

            // Now build it...
            Container = _builder.Build();
            Mediator = Container.Resolve<IMediator>();
        }
        #endregion
    }
}

所以，我的问题是:如何正确进行此注册?现在，有2或3个核心"(微服务)，但是下个月，20，明年，200等...

So, my question is: How do I correctly do this registration? Right now, 2 or 3 "cores" (micro-services) but next month, 20, next year, 200, etc...

TIA

推荐答案

您可以执行程序集扫描检索所需的所有程序集，然后以简单循环(未经测试的代码)注册它们:

Instead of manually register assembly by assembly, you could do Assembly Scanning to retrieve all assemblies you need, and then, register them in simple loop (code not tested):

var assemblies = /* get assemblies based on project type (web/desktop) */;
foreach(var assembly in assemblies)
{
    container.RegisterAssemblyTypes(assembly).AsImplementedInterfaces();
}

顺便说一句，除非您有很强的论点(服务定位器反模式)，否则不应将容器公开为公共属性.另外SingleInstanceFactory和MultiInstanceFactory对我来说也很可疑...

Btw, you should not expose your container as public property, unless you have very strong arguments to do so (service locator anti-pattern). Also SingleInstanceFactory and MultiInstanceFactory look pretty suspicious for me...

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