Resolve IEnumerable with Autofac

本文关键字：Autofac with IEnumerable Resolve | 更新日期: 2023-09-27 18:17:45

我正在尝试用Mediatr和Autofac构建一个中介管道，但我正在努力解决Autofac验证器的集合。

public class MediatorPipeline<TRequest, TResponse>
    : IAsyncRequestHandler<TRequest, TResponse> where TRequest : IAsyncRequest<TResponse>
{
    private readonly IAsyncRequestHandler<TRequest, TResponse> _inner;
    private readonly IEnumerable<IValidator<TRequest>> _validators;
    public MediatorPipeline(IAsyncRequestHandler<TRequest, TResponse> inner,
        IEnumerable<IValidator<TRequest>> validators)
    {
        _inner = inner;
        _validators = validators;
    }
    ...
}

当我把IValidator<TRequest>放入构造函数时，它解析得很好，但是当我把IEnumerable<IValidator<TRequest>>放入构造函数时，它失败了，除了:

容器或服务定位器未正确配置或处理程序未在容器中注册。--> autoface . core . dependencyresolutionexception:在激活特定注册时发生错误。

这是我的注册码: 
builder.RegisterAssemblyTypes(assembly)
    .Where(t => t.IsClosedTypeOf(typeof(IValidator<>)))
    .AsImplementedInterfaces()
    .InstancePerLifetimeScope();

我用这个替代注册得到了相同的结果:

var openGenericType = typeof(IValidator<>);
var query = from type in assembly.GetTypes().Where(c => !(c.GetTypeInfo().IsAbstract || c.GetTypeInfo().IsGenericTypeDefinition))
            let interfaces = type.GetInterfaces()
            let genericInterfaces = interfaces.Where(i => i.GetTypeInfo().IsGenericType && i.GetGenericTypeDefinition() == openGenericType)
            let matchingInterface = genericInterfaces.FirstOrDefault()
            where matchingInterface != null
            select new { matchingInterface, type };
foreach (var pair in query)
{
    builder.RegisterType(pair.type).As(pair.matchingInterface);
}

任何建议都非常感谢!

Resolve IEnumerable with Autofac

首先，很高兴看到整个异常-包括内部异常-与堆栈跟踪。

Autofac暴露了一个方便的扩展方法，AsClosedTypesOf，您可以这样使用:

builder
    .RegisterAssemblyTypes(ThisAssembly)
    .AsClosedTypesOf(typeof(IValidator<>))
    .InstancePerLifetimeScope();

这将为您完成工作，因此您不必深入思考注册验证器。

然后你需要在上面注册你的处理程序和装饰器:

builder
    .RegisterAssemblyTypes(ThisAssembly)
    .AsClosedTypesOf(typeof(IAsyncRequestHandler<,>), "base-handler")
    .InstancePerDependency();
builder.RegisterGenericDecorator(
    typeof(MediatorPipeline<,>),
    typeof(IAsyncRequestHandler<,>),
    "base-handler");
相关文章：