.Net Core 之AutoFac的使用

// 创建注册组件的builder
var builder = new ContainerBuilder();

//根据类型注册组件 ConsoleLogger 暴漏服务：ILogger
builder.RegisterType<ConsoleLogger>().As<ILogger>();

//根据类型注册组件 ConsoleLogger,暴漏其实现的所有服务（接口）
builder.RegisterType<ConsoleLogger>().AsImplementedInterfaces();

// 根据实例注册组件 output  暴漏服务：TextWriter
var output = new StringWriter();
builder.RegisterInstance(output).As<TextWriter>();

//表达式注册组件，这里我们是在构造函数时传参->"musection"   暴漏服务：IConfigReader
builder.Register(c =new ConfigReader("mysection")).As<IConfigReader>();

//表达式注册组件,解析时传参
var service = scope.Resolve<IConfigReader>(
           new NamedParameter("section", "mysection"));     

//反射注册组件，直接注册了ConsoleLogger类（必须是具体的类），如果ConsoleLogger有多个构造函数，将会取参数最多的那个构造函数进行实例化
builder.RegisterType<ConsoleLogger>();

//反射注册组件，手动指定构造函数，这里指定了调用 MyComponent（ILogger log,IConfigReader config）的构造函数进行注册
builder.RegisterType<MyComponent>()
 .UsingConstructor(typeof(ILogger), typeof(IConfigReader));  

 //注册MySingleton类中的静态变量"Instance"，ExternallyOwned()函数指定自己控制实例的生命周期，而不是由autofac自动释放
 builder.RegisterInstance(MySingleton.Instance).ExternallyOwned();

//一个组件暴漏两个服务  
builder.RegisterType<CallLogger>().As<ILogger>().As<ICallInterceptor>(); 

//注册当前程序集中以“Service”结尾的类
builder.RegisterAssemblyTypes(System.Reflection.Assembly.GetExecutingAssembly()).Where(t => t.Name.EndsWith("Service")).AsImplementedInterfaces();
//注册"MyApp.Repository"程序集中所有的类
builder.RegisterAssemblyTypes(GetAssembly("MyApp.Repository")).AsImplementedInterfaces();
  
//构建一个容器完成注册
var rootcontainer = builder.Build();

//可以通过下面这种方式手动获取IConfigReader 的实现类
//这种手动解析的方式需要 从生命周期作用域内获取组件,以保证组件最终被释放
//不要直接从根容器rootcontainer中解析组件，很有可能会导致内存泄漏
using(var scope = rootcontainer.BeginLifetimeScope())
{
  var reader = scope.Resolve<IConfigReader>();
}

  public static IContainer AutofacContainer;
    // This method gets called by the runtime. Use this method to add services to the container.
    public IServiceProvider ConfigureServices(IServiceCollection services)
    {
        //注册服务进 IServiceCollection
        services.AddMvc();
        ContainerBuilder builder = new ContainerBuilder();
        //将services中的服务填充到Autofac中.
        builder.Populate(services);
        //新模块组件注册
        builder.RegisterModule<DefaultModuleRegister>();
        //创建容器.
        AutofacContainer = builder.Build();
        //使用容器创建 AutofacServiceProvider 
        return new AutofacServiceProvider(AutofacContainer);
    }

public class DefaultModuleRegister : Module
{
    protected override void Load(ContainerBuilder builder)
    {
        //注册当前程序集中以“Ser”结尾的类,暴漏类实现的所有接口，生命周期为PerLifetimeScope
        builder.RegisterAssemblyTypes(System.Reflection.Assembly.GetExecutingAssembly()).Where(t => t.Name.EndsWith("Ser")).AsImplementedInterfaces().InstancePerLifetimeScope();
        builder.RegisterAssemblyTypes(System.Reflection.Assembly.GetExecutingAssembly()).Where(t => t.Name.EndsWith("Repository")).AsImplementedInterfaces().InstancePerLifetimeScope();
        //注册所有"MyApp.Repository"程序集中的类
        //builder.RegisterAssemblyTypes(GetAssembly("MyApp.Repository")).AsImplementedInterfaces();
    }

	public static Assembly GetAssembly(string assemblyName)
    {
        var assembly = AssemblyLoadContext.Default.LoadFromAssemblyPath(AppContext.BaseDirectory + $"{assemblyName}.dll");
        return assembly;
    }
}

  public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApplicationLifetime appLifetime)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseBrowserLink();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseStaticFiles();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
        //程序停止调用函数
        appLifetime.ApplicationStopped.Register(() => { AutofacContainer.Dispose(); });
    }

  private IUserSer _user;
    private IUserSer _user2;
    public HomeController(IUserSer user, IUserSer user2)
    {
        _user = user;
        _user2 = user2;
    }
    public IActionResult Index()
    {
        using (var scope = Startup.AutofacContainer.BeginLifetimeScope())
        {
            IConfiguration config = scope.Resolve<IConfiguration>();
            IHostingEnvironment env = scope.Resolve<IHostingEnvironment>();
        }
        string name = _user.GetName();
        string name2 = _user2.GetName();
        return View();
    }