C# 如何使用自定义工厂方法注册OpenGeneric?
TL;DR:我可以用Autofac创建一个通用工厂,这样我就可以注入C# 如何使用自定义工厂方法注册OpenGeneric?,c#,autofac,C#,Autofac,TL;DR:我可以用Autofac创建一个通用工厂,这样我就可以注入IProduct,而不是从IFactory任何我需要的地方解析它吗?有没有办法将解析从工厂任务移动到合成根目录 所以我使用的是第三方库,它公开了一些通过工厂创建的通用接口。出于演示目的,我们假设以下代码是库: 第三方库模型: public interface IFactory { IProduct<TModel> CreateProduct<TModel>(string identifier);
IProduct
,而不是从IFactory
任何我需要的地方解析它吗?有没有办法将解析从工厂任务移动到合成根目录
所以我使用的是第三方库,它公开了一些通过工厂创建的通用接口。出于演示目的,我们假设以下代码是库:
第三方库模型:
public interface IFactory
{
IProduct<TModel> CreateProduct<TModel>(string identifier);
}
internal class Factory : IFactory
{
private readonly string _privateData = "somevalues";
public IProduct<TModel> CreateProduct<TModel>(string identifier)
{
return new Product<TModel>(_privateData, identifier);
}
}
public interface IProduct<TModel>
{
void DoSomething();
}
internal sealed class Product<TModel>: IProduct<TModel>
{
private readonly string _privateData;
private readonly string _identifier;
public Product(string privateData, string identifier)
{
_privateData = privateData;
_identifier = identifier;
}
public void DoSomething()
{
System.Diagnostics.Debug.WriteLine($"{_privateData} + {_identifier}");
}
}
现在,让我们假设我想要MyService
中的ipproduct
。我需要在那里解决这个问题:
public class MyService
{
public MyService(IFactory factory)
{
IProduct<Shoe> shoeProduct = factory.CreateProduct<Shoe>("theshoe");
}
}
然后像这样注射
public class MyService
{
public MyService(IProduct<Shoe> shoeProduct) { }
}
但显然,这是一个糟糕的解决方案,原因有很多,最重要的是它容易受到库内部更改的影响
解决方案2:创建一个虚拟类型,并在激活时将其替换为:
Type factoryType = typeof(Factory);
Type factoryField = factoryType.GetField("_privateData", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Getfield);
Type productType = typeof(Product); // this is `internal` in the third party library, so I have to look it up from the assembly in reality
builder
.RegisterGeneric(productType)
.OnPreparing(preparing =>
{
var factory = preparing.Context.Resolve<IFactory>();
var privateFieldValue = factoryField.GetValue(factory);
var closedProductType = preparing.Component.Activator.LimitType;
var productModel = closedProductType.GetGenericArguments().Single();
var productIdentifier = productModel.GetGenericArgument<ProductIdentifierAttribute>().Identifier;
preparing.Parameters = new List<Parameter>()
{
new PositionalParameter(0, privateFieldValue),
new PositionalParameter(0, productIdentifier)
};
})
.AsImplementedInterfaces();
public class DummyProduct<TModel> : IProduct<TModel>
{
public void DoSomething() => throw new NotImplementedException("");
}
公共类DummyProduct:IPProduct
{
public void DoSomething()=>抛出新的NotImplementedException(“”);
}
因此,我们将其注册为开放泛型,并在注入之前替换其值:
MethodInfo openProductBuilder = this.GetType().GetMethod(nameof(CreateProduct), BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.InvokeMethod);
builder
.RegisterGeneric(typeof(DummyProduct<>))
.OnActivating(activating =>
{
var productModel = activating.Instance.GetType().GetGenericArguments().First();
var productIdentifier = productModel.GetGenericArgument<ProductIdentifierAttribute>().Identifier;
var factory = activating.Context.Resolve<IFactory>();
var closedProductBuilder = openProductBuilder.MakeGenericMethod(productModel);
object productObject = closedProductBuilder.Invoke(this, new object[] { factory, productIdentifier });
handler.ReplaceInstance(productObject);
})
.AsImplementedInterfaces();
MethodInfo openProductBuilder=this.GetType().GetMethod(nameof(CreateProduct),BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.InvokeMethod);
建设者
.RegisterGeneric(类型(DummyProduct))
.on激活(激活=>
{
var productModel=activating.Instance.GetType().GetGenericArguments().First();
var productIdentifier=productModel.GetGenericArgument().Identifier;
var factory=activating.Context.Resolve();
var closedProductBuilder=openProductBuilder.MakeGenericMethod(productModel);
object productObject=closedProductBuilder.Invoke(此,新对象[]{factory,productIdentifier});
ReplaceInstance(productObject);
})
.a实现接口();
我们有一个helper方法,因此我们只依赖于Mongo模块类中的反射方法:
私有IPProduct CreateProduct(IFactory工厂,字符串标识符)
{
返回工厂。CreateProduct(标识符);
}
现在,很明显,这比第一种方法要好,并且不依赖于太多的反射。不幸的是,每次我们想要真实的对象时,它都需要创建一个虚拟对象。真糟糕
问题:是否有其他方法使用Autofac进行此操作?我是否可以创建Autofac可以使用的通用工厂方法?我的主要目标是省去创建虚拟类型的过程,直接跳到调用CreateProduct
代码
注意事项:我删掉了一些错误检查,等。我通常会这样做,使这个问题尽可能简短,同时仍然充分演示问题和我当前的解决方案。如果您的工厂中没有非通用的创建方法,您将需要调用MakeGenericMethod
您可以使用IRegistrationSource
组件来执行与解决方案2中相同的操作,而不是激活事件
internal class FactoryRegistrationSource : IRegistrationSource
{
private static MethodInfo openProductBuilder = typeof(Factory).GetMethod(nameof(Factory.CreateProduct));
public Boolean IsAdapterForIndividualComponents => false;
public IEnumerable<IComponentRegistration> RegistrationsFor(Service service, Func<Service, IEnumerable<IComponentRegistration>> registrationAccessor)
{
IServiceWithType typedService = service as IServiceWithType;
if (typedService != null && typedService.ServiceType.IsClosedTypeOf(typeof(IProduct<>)))
{
IComponentRegistration registration = RegistrationBuilder.ForDelegate(typedService.ServiceType, (c, p) =>
{
IFactory factory = c.Resolve<IFactory>();
Type productModel = typedService.ServiceType.GetGenericArguments().First();
String productIdentifier = productModel.GetCustomAttribute<ProductIdentifierAttribute>()?.Identifier;
MethodInfo closedProductBuilder = openProductBuilder.MakeGenericMethod(productModel);
Object productObject = closedProductBuilder.Invoke(factory, new object[] { productIdentifier });
return productObject;
}).As(service).CreateRegistration();
yield return registration;
}
yield break;
}
}
内部类FactoryRegistrationSource:IRegistrationSource
{
私有静态MethodInfo openProductBuilder=typeof(Factory.GetMethod)(nameof(Factory.CreateProduct));
公共布尔值IsAdapterForIndividualComponents=>false;
公共IEnumerable Registrationfor(服务、函数注册接受器)
{
IServiceWithType typedService=作为IServiceWithType的服务;
if(typedService!=null&&typedService.ServiceType.IsClosedTypeOf(typeof(ipproduct)))
{
IComponentRegistration=RegistrationBuilder.ForDelegate(typedService.ServiceType,(c,p)=>
{
IFactory factory=c.Resolve();
类型productModel=typedService.ServiceType.GetGenericArguments().First();
字符串productIdentifier=productModel.GetCustomAttribute()?.Identifier;
MethodInfo closedProductBuilder=openProductBuilder.MakeGenericMethod(productModel);
Object productObject=closedProductBuilder.Invoke(工厂,新对象[]{productIdentifier});
返回产品对象;
}).As(service.CreateRegistration();
收益申报登记;
}
屈服断裂;
}
}
public class DummyProduct<TModel> : IProduct<TModel>
{
public void DoSomething() => throw new NotImplementedException("");
}
MethodInfo openProductBuilder = this.GetType().GetMethod(nameof(CreateProduct), BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.InvokeMethod);
builder
.RegisterGeneric(typeof(DummyProduct<>))
.OnActivating(activating =>
{
var productModel = activating.Instance.GetType().GetGenericArguments().First();
var productIdentifier = productModel.GetGenericArgument<ProductIdentifierAttribute>().Identifier;
var factory = activating.Context.Resolve<IFactory>();
var closedProductBuilder = openProductBuilder.MakeGenericMethod(productModel);
object productObject = closedProductBuilder.Invoke(this, new object[] { factory, productIdentifier });
handler.ReplaceInstance(productObject);
})
.AsImplementedInterfaces();
private IProduct<TModel> CreateProduct<TModel>(IFactory factory, string identifier)
{
return factory.CreateProduct<TModel>(identifier);
}
internal class FactoryRegistrationSource : IRegistrationSource
{
private static MethodInfo openProductBuilder = typeof(Factory).GetMethod(nameof(Factory.CreateProduct));
public Boolean IsAdapterForIndividualComponents => false;
public IEnumerable<IComponentRegistration> RegistrationsFor(Service service, Func<Service, IEnumerable<IComponentRegistration>> registrationAccessor)
{
IServiceWithType typedService = service as IServiceWithType;
if (typedService != null && typedService.ServiceType.IsClosedTypeOf(typeof(IProduct<>)))
{
IComponentRegistration registration = RegistrationBuilder.ForDelegate(typedService.ServiceType, (c, p) =>
{
IFactory factory = c.Resolve<IFactory>();
Type productModel = typedService.ServiceType.GetGenericArguments().First();
String productIdentifier = productModel.GetCustomAttribute<ProductIdentifierAttribute>()?.Identifier;
MethodInfo closedProductBuilder = openProductBuilder.MakeGenericMethod(productModel);
Object productObject = closedProductBuilder.Invoke(factory, new object[] { productIdentifier });
return productObject;
}).As(service).CreateRegistration();
yield return registration;
}
yield break;
}
}