一、背景

　　刚接触.net 6，记录一下在.net6上是怎么使用Autofac进行动态的依赖注入的

二、注入方式

　　1、新建一个webapi项目，框架选择net 6

　　2、引用Nuget包---Autofac.Extensions.Dependency　　

　　3、在Program.cs上添加如下代码

//依赖注入
builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory())//注册服务工厂
.ConfigureContainer<ContainerBuilder>(container =>
{　　//添加依赖注入，AddModule是一个自定义的拓展方法，将依赖注入的方法单独提取出来，方便管理builder.Services.AddModule(container);
});

public static IServiceCollection AddModule(this IServiceCollection services, ContainerBuilder builder, IConfiguration configuration){//初始化配置文件Type baseType = typeof(IDependency);//自定义的空类//动态运行项目的类库var compilationLibrary = DependencyContext.Default.RuntimeLibraries.Where(x => !x.Serviceable&& x.Type == "project").ToList();var count1 = compilationLibrary.Count;List<Assembly> assemblyList = new List<Assembly>();foreach (var _compilation in compilationLibrary){try{assemblyList.Add(AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(_compilation.Name)));}catch (Exception ex){Console.WriteLine(_compilation.Name + ex.Message);}}//注册程序集的方式添加依赖builder.RegisterAssemblyTypes(assemblyList.ToArray()).Where(type => baseType.IsAssignableFrom(type) && !type.IsAbstract)//过滤非抽象类，继承了IDependency接口的类.AsSelf().AsImplementedInterfaces().InstancePerLifetimeScope();//实例的生命周期//单独注册依赖服务//注册数据库基础操作和工作单元builder.RegisterGeneric(typeof(BaseRepository<,>)).As(typeof(IRepository<,>));builder.RegisterGeneric(typeof(UnitWork<>)).As(typeof(IUnitWork<>));//注册app层builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly());builder.RegisterType(typeof(RedisCacheContext)).As(typeof(ICacheContext));builder.RegisterType<MemoryCacheService>().As<ICacheService>().SingleInstance();return services;}

4.

或

//依赖注入
builder.Host.UseServiceProviderFactory(new AutofacServiceProviderFactory())

以及再startup.cs中添加ConfigureContainer方法

   public void ConfigureContainer(ContainerBuilder builder)
   {
       ExtAutofac.InitAutofac(builder);
   }

在app层

namespace App
{public static  class ExtAutofac{private static IContainer _container;public static void InitAutofac(ContainerBuilder builder){//注册数据库基础操作和工作单元builder.RegisterGeneric(typeof(BaseRepository<,>)).As(typeof(IRepository<,>));builder.RegisterGeneric(typeof(UnitWork<>)).As(typeof(IUnitWork<>));//注册app层builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly());builder.RegisterType(typeof(RedisCacheContext)).As(typeof(ICacheContext));builder.RegisterType(typeof(HttpContextAccessor)).As(typeof(IHttpContextAccessor));InitDependency(builder);}/// <summary>/// 注入所有继承了IDependency接口/// </summary>/// <param name="builder"></param>private static void InitDependency(ContainerBuilder builder){Type baseType = typeof(IDependency);var compilationLibrary = DependencyContext.Default.CompileLibraries.Where(x => !x.Serviceable&& x.Type == "project").ToList();var count1 = compilationLibrary.Count;List<Assembly> assemblyList = new List<Assembly>();foreach (var _compilation in compilationLibrary){try{assemblyList.Add(AssemblyLoadContext.Default.LoadFromAssemblyName(new AssemblyName(_compilation.Name)));}catch (Exception ex){Console.WriteLine(_compilation.Name + ex.Message);}}builder.RegisterAssemblyTypes(assemblyList.ToArray()).Where(type => baseType.IsAssignableFrom(type) && !type.IsAbstract).AsSelf().AsImplementedInterfaces().InstancePerLifetimeScope();}}
}