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我正在尝试执行以下操作：

public interface IExampleDto { }

public class ExampleClass1 : IExampleDto { )
public class ExampleClass2 : IExampleDto { )

public class ExampleQuery<TProjection> : IRequest<TProjection>
    where TProjection : IExampleDto
{
    public Guid Id { get; set; }
}

public class ExampleQueryHandler<TProjection> : IRequestHandler<ExampleQuery<TProjection>, TProjection>
   where TProjection : IExampleDto
{
    public async Task<TProjection> Handle(ExampleQuery<TProjection> request, CancellationToken cancellationToken)
    {
        return await _context.Example.Where(e => e.Id == request.Id)
            .ProjectTo<TProjection>(_mapper.ConfigurationProvider).FirstOrDefaultAsync(cancellationToken);
    }
}

我的 Autofac 配置如下：

protected override void Load(ContainerBuilder builder)
    {
        builder.RegisterAssemblyTypes(typeof(IMediator).GetTypeInfo().Assembly)
            .InstancePerLifetimeScope()
            .AsImplementedInterfaces();
         
        // Register all the Command classes (they implement IRequestHandler) in assembly holding the Commands
        builder.RegisterAssemblyTypes(typeof(UpdateElementTypeCommand).GetTypeInfo().Assembly)
            .AsClosedTypesOf(typeof(IRequestHandler<,>))
            .AsImplementedInterfaces()
            .InstancePerDependency();

        // Register the DomainEventHandler classes (they implement INotificationHandler<>) in assembly holding the Domain Events
        builder.RegisterAssemblyTypes(typeof(ElementDomainEventHandler).GetTypeInfo().Assembly)
            .AsClosedTypesOf(typeof(INotificationHandler<>));

        // Register the Command's Validators (Validators based on FluentValidation library)
        builder
            .RegisterAssemblyTypes(typeof(CreateNewCategoryCommandValidator).GetTypeInfo().Assembly)
            .Where(t => t.IsClosedTypeOf(typeof(IValidator<>)))
            .AsImplementedInterfaces();

        builder.Register<ServiceFactory>(context =>
        {
            var componentContext = context.Resolve<IComponentContext>();
            return t => { object o; return componentContext.TryResolve(t, out o) ? o : null; };
        });

        builder.RegisterGeneric(typeof(LoggingBehavior<,>)).As(typeof(IPipelineBehavior<,>)).AsImplementedInterfaces();
        builder.RegisterGeneric(typeof(ValidatorBehavior<,>)).As(typeof(IPipelineBehavior<,>)).AsImplementedInterfaces();
        builder.RegisterGeneric(typeof(TransactionBehaviour<,>)).As(typeof(IPipelineBehavior<,>)).AsImplementedInterfaces();
    }

当我执行请求时：

await _mediator.Send(new ExampleQuery<ExampleClass1> { Id = id })

我收到以下错误：

System.InvalidOperationException：'找不到处理程序类型为 MediatR.IRequestHandler`2[ExampleQuery[ExampleClass1]，ExampleClass1] 的请求。向容器注册您的处理程序。

我了解运行时无法找到具有提供的类的处理程序，因为它尚未正确注册。我想要实现的目标真的可能吗？我缺少 Autofac 配置中的任何内容吗？

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0 回答 0