IOC容器2

一、.NetCore 2.2版本

RegisterType以普通类注册方式

1、搭建.Net Core 2.2 项目，并添加组件

2、创建Common类库，并添加TestService类

代码如下：

using System;

namespace Common
{
    public class TestService 
    {
        public string GetName()
        {
            return "功能点1";
        }
    }
}

3、配置

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
using Autofac;
using Autofac.Extensions.DependencyInjection;
using Common;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace Core2._2
{
    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 IServiceProvider ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

            //注册Autofac组件
            return AutofacComponent.Register(services);
        }
        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseMvc();
        }
    }
    public class AutofacComponent
    {
        /// <summary>
        /// 注册Autofac组件
        /// </summary>
        /// <param name="services"></param>
        /// <returns></returns>
        public static IServiceProvider Register(IServiceCollection services)
        {
            //实例化Autofac容器
            ContainerBuilder builder = new ContainerBuilder();
            //将collection中的服务填充到Autofac
            builder.Populate(services);
            //注册InstanceModule组件
            builder.RegisterModule<InstanceModule>();
            //创建容器
            IContainer container = builder.Build();
            //第三方容器接管Core内置的DI容器
            return new AutofacServiceProvider(container);
        }
    }
    public class InstanceModule : Autofac.Module
    {
        //重写Autofac管道中的Load方法，在这里注入注册的内容
        protected override void Load(ContainerBuilder builder)
        {
            //以普通类的形式注册PlayPianoService
            builder.RegisterType<TestService>();
        }
    }
}

4、访问

 代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Common;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace Core2._2.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    public class HomeController : ControllerBase
    {
        private readonly TestService _testService;
        public HomeController(TestService testService)
        {
            _testService = testService;
        }
        // GET: api/<controller>
        [HttpGet]
        public IEnumerable<string> Get()
        {
            var str = _testService.GetName();

            return new string[] { "value1", "value2" };
        }
    }
}

RegisterAssemblyTypes 查找匹配的类型注入方式

1、配置RegisterAssemblyTypes自动注入方式映射接口和实现类

 代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;
using Autofac;
using Autofac.Extensions.DependencyInjection;
using Common;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;

namespace Core2._2
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }
        public IConfiguration Configuration { get; }
        public IContainer ApplicationContainer { get; private set; }
        // This method gets called by the runtime. Use this method to add services to the container.
        public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
            //初始化容器
            var builder = new ContainerBuilder();
            //管道寄居
            builder.Populate(services);
            //业务逻辑层所在程序集命名空间
            Assembly service = Assembly.Load("Common");
            //接口层所在程序集命名空间
            Assembly repository = Assembly.Load("Common");
            //自动注入
            builder.RegisterAssemblyTypes(service, repository)
                .Where(t => t.Name.EndsWith("Service"))
                .AsImplementedInterfaces();
            //构造
            ApplicationContainer = builder.Build();
            //将AutoFac反馈到管道中
            return new AutofacServiceProvider(ApplicationContainer);
        }
        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            app.UseMvc();
        }
    }
}

或者直接这样

2、Common类

 代码如下：

using System;

namespace Common
{
    public interface ITestService
    {
        string GetName();
    }

    public class TestService: ITestService
    {
        public string GetName()
        {
            return "功能点1";
        }
    }
}

访问

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Common;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace Core2._2.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    public class HomeController : ControllerBase
    {
        private readonly ITestService _testService;
        public HomeController(ITestService testService)
        {
            _testService = testService;
        }
        // GET: api/<controller>
        [HttpGet]
        public IEnumerable<string> Get()
        {
            var str = _testService.GetName();

            return new string[] { "value1", "value2" };
        }
    }
}

 注意：RegisterAssemblyTypes 自动注入方式 接口注入方式（不可以通过实现类注入）否则：

RegisterGeneric泛型的具体对象的方式

1、

二、.NET Core 3.0

1、修改 Program.cs 将默认ServiceProviderFactory指定为AutofacServiceProviderFactory

 代码如下：

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

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

2、然后在 Startup.cs 中添加 ConfigureContainer 方法

使用ConfigureContainer访问Autofac容器生成器，并直接向Autofac注册。

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

namespace IOCTest
{
    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) //Core 3.0 3.1 此方法都是void 类型   2.1 2.2则是返回IServiceCollection
        {
            services.AddControllers();
        }

        public void ConfigureContainer(ContainerBuilder builder)
        {
            //业务逻辑层所在程序集命名空间
            Assembly service = Assembly.Load("Common");
            //接口层所在程序集命名空间
            Assembly repository = Assembly.Load("Common");
            //自动注入
            builder.RegisterAssemblyTypes(service, repository)
                .Where(t => t.Name.EndsWith("Service"))
                .AsImplementedInterfaces();
            //注册仓储，所有IRepository接口到Repository的映射
        }
        // 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();
            }

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }

}

3、类库方法接口和实现类

 4、访问

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Common;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace IOCTest.Controllers
{
    [Route("api/[controller]/[action]")]
    [ApiController]
    public class HomeController : ControllerBase
    {
        private readonly ITestService _testService;
        public HomeController(ITestService testService)
        {
            _testService = testService;
        }
        // GET: api/<controller>
        [HttpGet]
        public IEnumerable<string> Get()
        {
            var str=_testService.GetName();

            return new string[] { "value1", "value2" };
        }
    }
}