使用VS Code开发.NET Core 0006 - 使用Autofac 实现自动依赖注入

一、创建类库 Extensions，并且安装 Autofac 依赖

安裝两个 Nugget 包：Autofac.Extensions.DependencyInjection 和 Autofac.Extras.DynamicProxy

  <ItemGroup>
    <PackageReference Include="Autofac.Extensions.DependencyInjection" Version="7.1.0"/>
    <PackageReference Include="Autofac.Extras.DynamicProxy" Version="6.0.0"/>
  </ItemGroup>

二、封装 AutofacModuleRegister.cs

    public class AutofacModuleRegister : Autofac.Module
    {
        // private static readonly ILog log = LogManager.GetLogger(typeof(AutofacModuleRegister));
        protected override void Load(ContainerBuilder builder)
        {
            var basePath = AppContext.BaseDirectory;

            #region 带有接口层的服务注入
            var servicesDllFile = Path.Combine(basePath, "Services.dll");
            var repositoryDllFile = Path.Combine(basePath, "Repository.dll");
            if (!(File.Exists(servicesDllFile) && File.Exists(repositoryDllFile)))
            {
                var msg = "Repository.dll和service.dll 丢失，因为项目解耦了，所以需要先F6编译，再F5运行，请检查 bin 文件夹";
                // log.Error(msg);
                throw new Exception(msg);
            }

            // builder.RegisterGeneric(typeof(BaseRepository<>)).As(typeof(IBaseRepository<>)).InstancePerDependency();//注册仓储
            builder.RegisterGeneric(typeof(BaseRepository<,>)).As(typeof(IBaseRepository<,>)).InstancePerDependency();//注册仓储

            // 获取 Service.dll 程序集服务，并注册
            var assemblyServices = Assembly.LoadFrom(servicesDllFile);
            builder.RegisterAssemblyTypes(assemblyServices)
                      .AsImplementedInterfaces()
                      .InstancePerDependency()
            .EnableInterfaceInterceptors();//引用Autofac.Extras.DynamicProxy;
            //.InterceptedBy(cacheType.ToArray());//允许将拦截器服务的列表分配给注册。

            // 获取 Repository.dll 程序集服务，并注册
            var assemblyRepository = Assembly.LoadFrom(repositoryDllFile);
            builder.RegisterAssemblyTypes(assemblyRepository)
                   .AsImplementedInterfaces()
                   .InstancePerDependency();


            #endregion

        }
    }

三、在 Program 中 Autofac 服务工厂

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

四、在 Startup 中

        // 注意，要在 Program 中 添加 AutofacServiceProviderFactory
        public void ConfigureContainer(ContainerBuilder builder)
        {
            builder.RegisterModule(new AutofacModuleRegister());
        }