使用Autofac与XML配置

Question

我想解耦一个实现，其中的接口是知道的，实现将在App.Config中定义。但它似乎无法解析界面。

这是我在做什么：

<configuration> 
    <autofac defaultAssembly="My.Service">  
    <components> 
     <component type="My.Services.Service, My.Service" 
       service="My.Abstractions.IService, My.Service" 
       instance-scope="per-lifetime-scope" 
       instance-ownership="lifetime-scope" 
       name="Service" 
       inject-properties="no"/> 
    </components>  
    </autofac> 
</configuration> 

而且在我的C＃代码

var builder = new ContainerBuilder(); 
builder.RegisterModule(new ConfigurationSettingsReader("autofac")); 
var container = builder.Build(); 
IService service = container.Resolve<IService>() 

当我运行的代码是不能够解决IService，这正是我需要的。 如果我这样做，但在代码而不是xml的实现，这是它的工作原理。

var builder = new ContainerBuilder(); 
builder.RegisterType<Service>().As<IService>().InstancePerLifetimeScope(); 
var container = builder.Build(); 
IService service = container.Resolve<IService>() 

这里是堆栈跟踪

An exception occurred creating the service: IService ---> Autofac.Core.Registration.ComponentNotRegisteredException: 
The requested service 'My.Abstractions.IService' has not been registered. 
To avoid this exception, either register a component to provide the service, 
check for service registration using IsRegistered(), 
or use the ResolveOptional() method to resolve an optional dependency. 
    at Autofac.ResolutionExtensions.ResolveService(IComponentContext context, Service service, IEnumerable`1 parameters) 
    at Autofac.ResolutionExtensions.Resolve(IComponentContext context, Type serviceType, IEnumerable`1 parameters) 
    at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context,IEnumerable`1 parameters) 
    at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context) 

任何人都可以解释我怎么可以使用XML配置解析时的界面？

Answer 1

错误来自配置文件中指定的name属性。

<component 
     type="My.Services.Service, My.Service" 
     service="My.Abstractions.IService, My.Service" 
     instance-scope="per-lifetime-scope" 
     instance-ownership="lifetime-scope" 
     name="Service" 
     inject-properties="no"/> 

等同于：

builder.RegisterType<Service>() 
     .Named<IService>("Service") 
     .InstancePerLifetimeScope(); 

有你想要的东西，只是去掉name属性，你不需要指定默认值。

<component 
     type="My.Services.Service, My.Service" 
     service="My.Abstractions.IService, My.Service" 
     instance-scope="per-lifetime-scope" />