.net core 模拟发布订阅

新建项目：WebApplication.Test

Nuget:

Autofac.Extensions.DependencyInjection
Newtonsoft.Json

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Autofac.Extensions.DependencyInjection;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace WebApplication.Test
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .UseServiceProviderFactory(new AutofacServiceProviderFactory())//autofac
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup<Startup>();
                });
    }
}

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Autofac;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace WebApplication.Test
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllersWithViews();
        }

        // ConfigureContainer is where you can register things directly
        // with Autofac. This runs after ConfigureServices so the things
        // here will override registrations made in ConfigureServices.
        // Don't build the container; that gets done for you by the factory.
        public void ConfigureContainer(ContainerBuilder builder)
        {
            // Register your own things directly with Autofac, like:
            builder.RegisterModule(new MyApplicationModule());//autofac
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }
            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Home}/{action=Index}/{id?}");
            });
        }
    }
}

 

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using WebApplication.Test.Models;

namespace WebApplication.Test.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;
        private readonly IServiceProvider _serviceProvider;
        public HomeController(ILogger<HomeController> logger, IServiceProvider serviceProvider)
        {
            _logger = logger;
            _serviceProvider = serviceProvider;
        }

        public IActionResult Index()
        {
            //json 序列化CustomEvent
            var json = Newtonsoft.Json.JsonConvert.SerializeObject(new CustomEvent { Name = "MY" });

            //根据type反序列化数据
            var type = GetCustomType<CustomEvent>();
            var customEvent = Newtonsoft.Json.JsonConvert.DeserializeObject(json, type);

            //模拟发布订阅，使用事件名称作为key存储相关订阅信息
            var eventName = nameof(CustomEvent);
            var subscription = new Dictionary<string, List<SubscriptionInfo>> { { eventName, new List<SubscriptionInfo> { new SubscriptionInfo(typeof(CustomEvent), typeof(IEventHandler<CustomEvent>)) } } };

            //创建新的生命周期执行订阅的处理程序
            using (var scope = _serviceProvider.CreateScope())
            {
                foreach (var subscriptionInfo in subscription[eventName])
                {
                    //订阅的处理程序已在应用启动时通过泛型方式全部注入到容器中
                    var handler = scope.ServiceProvider.GetRequiredService(subscriptionInfo.HandlerType);

                    //创建泛型精确类
                    var concreteType = typeof(IEventHandler<>).MakeGenericType(subscriptionInfo.EventType);
                    //使用反射执行处理方法
                    concreteType.GetMethod("Handle").Invoke(handler, new object[] { customEvent });
                }
            }
            return View();
        }


        public Type GetCustomType<T>()
        {
            return typeof(T);
        }

    }
}

 

 

using Autofac;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication.Test
{
    public class MyApplicationModule : Module
    {
        protected override void Load(ContainerBuilder builder)
        {
            builder.RegisterAssemblyTypes(typeof(CustomEventHandler).Assembly)
                   .AsClosedTypesOf(typeof(IEventHandler<>));
        }
    }
}

 

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication.Test
{
    public interface IEvent
    {
    }
}

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication.Test
{
    public interface IEventHandler<in TEvent> where TEvent : IEvent
    {
        void Handle(TEvent @event);
    }
}

 

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication.Test
{
    public class CustomEvent: IEvent
    {
        public string Name { get; set; }
    }
}

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebApplication.Test
{
    public class CustomEventHandler : IEventHandler<CustomEvent>
    {

        private readonly IServiceProvider _serviceProvider;

        public CustomEventHandler(IServiceProvider serviceProvider)
        {
            _serviceProvider = serviceProvider;
        }

        public void Handle(CustomEvent @event)
        {
             
        }
    }
}