此解析操作已经结束。 Autofac、Automapper 和 IMemberValueResolver

我对 Autofac 和 Automapper 有疑问。

在我的 WebApi 中，我有以下代码来注册我的类：

    public static void Initialize(HttpConfiguration config, IContainer container)
        {
            config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
            _container = container;
        }

        private static IContainer RegisterServices(ContainerBuilder builder)
        {
            //Register your Web API controllers.  
            builder.RegisterApiControllers(Assembly.GetExecutingAssembly());

            builder.RegisterModule<MapperInstaller>();
            builder.RegisterType<VurpEntities>();
            builder.RegisterType<EntityFrameworkUnitOfWork>().As<IUnitOfWork>();

            builder.RegisterType<AppService>().As<IAppService>();
            builder.RegisterType<AppRepository>().As<IAppRepository>();

            builder.RegisterType<BusinessService>().As<IBusinessService>();
            builder.RegisterType<BusinessRepository>().As<IBusinessRepository>();

//...
//all my types are registered here
//...



            //Set the dependency resolver to be Autofac.  
            _container = builder.Build();

            return _container;
        }

我创建了一个解析器来映射对象的特殊字段：

public class ProductTypeResolver : IMemberValueResolver<ProductDto, Product, string, Enumeration.ProductType>
    {
        public ProductType Resolve(ProductDto source, Product destination, string sourceMember, ProductType destMember, ResolutionContext context)
        {
            Enum.TryParse(sourceMember, out destMember);

            return destMember;
        }
    }

我有一个在实体对象中映射 DTO 对象的配置文件：

CreateMap<ProductDto, Product>()
            .ForMember(dest => dest.Category, opt => opt.Ignore())
            .ForMember(dest => dest.Feature, opt => opt.Ignore())
opts.ResolveUsing<ProductTypeResolver, string>(src => src.type));

当我尝试映射对象时Product p = _mapper.Map<Product>(productDto);我收到错误：

发生“System.ObjectDisposeException”类型的异常 Autofac.dll 但未在用户代码中处理

附加信息：此解析操作已结束。什么时候 使用 lambda 注册组件，IComponentContext 'c' 无法存储 lambda 的参数。相反，要么解决 再次从 'c' 调用 IComponentContext，或者将基于 Func 的工厂解析为 从中创建后续组件。

有人可以帮助我吗？

我用这个解决了：

    builder.Register(c =>
    {
        //This resolves a new context that can be used later.
        var context = c.Resolve<IComponentContext>();
        var config = context.Resolve<MapperConfiguration>();
        return config.CreateMapper(context.Resolve);
    })
    .As<IMapper>()
    .InstancePerLifetimeScope();