我正在尝试在DI容器中注册嵌套的泛型类型,但无法注册
I am trying to register the nested generic type in DI container, but unable to register
抛出{开放的泛型服务类型需要注册开放的泛型实现类型。 (参数描述符)}错误
throws {Open generic service type requires registering an open generic implementation type. (Parameter descriptors)} error
实现的接口方法如下:
public class CustomerEvent<TEntity> : IEventConsumer<EntityInsertedEvent<TEntity>>, IEventConsumer<EntityUpdatedEvent<TEntity>>, IEventConsumer<EntityDeletedEvent<TEntity>> where TEntity : BaseEntity { public void HandleEvent(EntityInsertedEvent<TEntity> eventMessage) { throw new NotImplementedException("Inserted"); } public void HandleEvent(EntityUpdatedEvent<TEntity> eventMessage) { throw new NotImplementedException("Updated"); } public void HandleEvent(EntityDeletedEvent<TEntity> eventMessage) { throw new NotImplementedException("Deleted"); } }尝试
Assembly.GetExecutingAssembly() .GetTypes() .Where(item => item.GetInterfaces() .Where(i => i.IsGenericType) .Any(i => i.GetGenericTypeDefinition() == typeof(IEventConsumer<>)) && !item.IsAbstract && !item.IsInterface) .ToList().ForEach(assignedTypes => { assignedTypes.GetInterfaces() .Where(i => i.GetGenericTypeDefinition() == typeof(IEventConsumer<>)).ToList() .ForEach(imp => { services.AddScoped(imp, assignedTypes); }); });但失败
推荐答案没有简单的方法可以做到这一点。通常,您需要将开放通用的抽象映射到开放通用的实现,例如:
There is no easy way to do this. Typically, you need to map an open-generic abstraction to an open-generic implementation, like this:
services.AddTransient(typeof(IEventConsumer<>), typeof(CustomerEvent<>));但是,这在您的情况下不起作用,因为MS.DI无法弄清楚该类的泛型类型参数如何 IEventCustomer< T> 应该映射到 CustomerEvent< TEntity> 的通用类型参数。例如,在解析 IEventCustomer< EntityInsertedEvent< Order>> 时,它将尝试创建 CustomerEvent< EntityInsertedEvent< Order>> ,尽管它应该已经创建了 CustomerEvent< Order> 。
This, however, will not work in your case because MS.DI is unable to figure out how the generic type argument for IEventCustomer<T> should maps to the generic type argument of CustomerEvent<TEntity>. When resolving an IEventCustomer<EntityInsertedEvent<Order>>, for instance, it will try to create a CustomerEvent<EntityInsertedEvent<Order>>, while it should have been creating a CustomerEvent<Order>.
这不是.NET的限制或CLR,但是它是MS.DI DI容器特有的限制,因为其他一些DI容器实际上能够进行此类映射。
This is not a limitation of .NET or the CLR, but a limitation that is specific to the MS.DI DI Container, because some other DI Containers are actually able to make these kinds of mappings.
不幸的是,使用MS.DI ,没有简单的出路。您唯一可以做的就是显式地进行所有可能的封闭通用注册,例如:
Unfortunately, with MS.DI, there is no easy way out. The only thing you can do is making all possible closed-generic registrations explicitly, e.g.:
s.AddTransient<IEventConsumer<EntityInsertedEvent<Order>>, CustomerEvent<Order>>(); s.AddTransient<IEventConsumer<EntityInsertedEvent<Customer>>, CustomerEvent<Customer>>(); s.AddTransient<IEventConsumer<EntityInsertedEvent<Product>>, CustomerEvent<Product>>(); s.AddTransient<IEventConsumer<EntityInsertedEvent<Employee>>, CustomerEvent<Employee>>(); s.AddTransient<IEventConsumer<EntityInsertedEvent<etc>>, CustomerEvent<etc>>();更多推荐
无法在.NET Core中注册嵌套的通用接口
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