您如何提供 Autofac 中的特定注册作为其他注册的参数？

Question

能否就如何将一些引用传递给其他注册提供一些指导？

//registration of 1st http client
    builder.RegisterType<HttpClient>()
      //.Keyed<HttpMessageInvoker>("authHttpClient")
     .WithProperties(new[] { new NamedPropertyParameter("PooledConnectionLifetime", 2 })
     .WithProperties(new[] { new NamedPropertyParameter("BaseAddress", "whatever"))})
     .SingleInstance();

//registration of 2nd httpclient
    builder.RegisterType<HttpClient>()
     .Keyed<HttpMessageInvoker>("dynamicsHttpClient")
     .WithProperties(new[] { new NamedPropertyParameter("PooledConnectionLifetime", 20) })
     .WithProperties(new[] { new NamedPropertyParameter("BaseAddress", "other something" })
    .SingleInstance();


// **I need to  do the registration of type and pass the 1st httpClient registration**
builder.RegisterType<DynamicsAuthApiGateway>()
    .As<IDynamicsAuthApiGateway>()

// **I need to do the registration of type pass 2nd instance of httpClient registration**
builder.RegisterType<DynamicsApiGateway>()
                .As<IDynamicsApiGateway>()
                .SingleInstance();

//Method ctor's
//DynamicsAuthApiGateway(**HttpClient client**, DynamicsAuthApiGatewaySettings apiGatewaySettings)
//DynamicsApiGateway(**HttpClient client**, Func<HttpResponseMessage, Task> errorHandler = null)

你能帮忙说说如何实现吗？

任何帮助将不胜感激？

谢谢，我

Answer 1

您使用密钥服务的方向正确。 Docs here for details and examples.

最简单的方法是使用 Autofac.Features.AttributeFilters.KeyFilterAttribute 来标记消费 class 上的构造函数。

首先，更新消费者。这是一个例子。

public class DynamicsAuthApiGateway : IDynamicsAuthApiGateway
{
  // KeyFilterAttribute on the parameter
  public DynamicsAuthApiGateway([KeyFilter("authHttpClient")] HttpClient client)
  {
    // ...
  }
}

然后注册键控客户端并在消费者上启用属性过滤。

// Don't forget
// using Autofac.Features.AttributeFilters;
// at the top... then:

// Register the HttpClient instances with keys
// and be sure the key is on the same type/interface
// as you see in the constructor of the consumer.
builder.RegisterType<HttpClient>()
       .Keyed<HttpClient>("authHttpClient")
       .SingleInstance();
builder.RegisterType<HttpClient>()
       .Keyed<HttpClient>("dynamicsHttpClient")
       .SingleInstance();

// Register the consumers and enable attribute filters
builder.RegisterType<DynamicsAuthApiGateway>()
       .As<IDynamicsAuthApiGateway>()
       .WithAttributeFiltering();
builder.RegisterType<DynamicsApiGateway>()
       .As<IDynamicsApiGateway>()
       .SingleInstance()
       .WithAttributeFiltering();

您必须选择加入属性过滤，因为如果您不需要它会产生额外的性能开销。如果您不输入 WithAttributeFiltering() 部分，则不会进行过滤。

如果你不想在你的 class 中使用该属性（例如，你想避免将 Autofac 绑定到事物中）那么它有点难 - 你需要使用 ResolvedParameter（ docs here).

看起来更像这样（我有点想把它写下来，所以如果有错别字之类的，你已经被警告过，但基本上应该是）...

// Register the HttpClient instances with keys
// and be sure the key is on the same type/interface
// as you see in the constructor of the consumer.
builder.RegisterType<HttpClient>()
       .Keyed<HttpClient>("authHttpClient")
       .SingleInstance();

// Register the consumers using resolved parameters.
builder.RegisterType<DynamicsAuthApiGateway>()
       .As<IDynamicsAuthApiGateway>()
       .WithParameter(
         new ResolvedParameter(
           (pi, ctx) => pi.ParameterType == typeof(HttpClient),
           (pi, ctx) => ctx.ResolveKeyed<HttpClient>("authHttpClient")));

它不是很干净，但它使 Autofac 引用远离消费者（如果重要的话）。如果你经常使用它，你可以编写自己的扩展方法以使其更容易。我将把它留作 reader.

的练习

您如何提供 Autofac 中的特定注册作为其他注册的参数？

How do you provide specific registrations in Autofac as parameters to other registrations?

autofac

autofac-module