[英]Inject an IEnumerable of generic interface in Unity Dependency Injection c#
I am working on a web API 2 application and using Unity dependency injection. 我正在使用Web API 2应用程序并使用Unity依赖项注入。
I have multiple types of filters: Name, Brand, Types ... 我有多种类型的过滤器:名称,品牌,类型...
I want to make an interface called: IFilterService and force every other class to implement it and then I call an IEnumerable of this interface and inject it with the correct type. 我想创建一个名为:IFilterService的接口,并强制其他所有类都实现它,然后调用此接口的IEnumerable并将其注入正确的类型。
the interface is: 界面是:
public interface IFilterService<T>
{
bool CanHandle(FilterType type);
Task<ServiceResult<T>> FilterAsync(T entity);
}
and the classes are like: 和类是这样的:
public class NameService : IFilterService<Name>
{
public bool CanHandle(FacetType type)
{
return type == FacetType.Name;
}
public async Task<ServiceResult<Name>> FilterAsync(Name entity)
{
// Code
}
}
the controller is like: 控制器就像:
public class FilterController
{
private readonly IEnumerable<IFilterService> filters;
public MediaController(IEnumerable<IFilterService> filters)
{
this.filters = filters;
}
public async Task<HttpResponseMessage> FilterAsync(FilterType type, Name entity)
{
foreach(var filter in this.filters.Where(x => x.CanHandle(type)))
{
filter.FilterAsync(entity);
}
....
}
}
everything is working correctly: the only problem is with registering the interface and the classes in the Unity Dependency Injection. 一切工作正常:唯一的问题是在Unity Dependency Injection中注册接口和类。
container.RegisterType<IEnumerable<IFilterService>, IFilterService[] >(
new ContainerControlledLifetimeManager());
container.RegisterType<IFilterService, NameService>("Name Service",
new ContainerControlledLifetimeManager());
I am receiving this error: 我收到此错误:
Error CS0305 Using the generic type 'IFilterService' requires 1 type arguments
错误CS0305使用通用类型“ IFilterService”需要1个类型参数
The same code I've tried it but with a non-generic interface and works fine. 我尝试过的相同代码,但是具有非通用接口,可以正常工作。
how to fix the error? 如何解决错误? and a little explanation could be very useful.
并作一些解释可能非常有用。 thank you.
谢谢。
You have two options, the first is to register the specific filter type 您有两个选择,第一个是注册特定的过滤器类型
container.RegisterType<IEnumerable<IFilterService<Name>>, IFilterService<Name>[] >(
new ContainerControlledLifetimeManager());
container.RegisterType<IFilterService<Name>, NameService>("Name Service",
new ContainerControlledLifetimeManager());
Used like 使用像
public class FilterController
{
private readonly IEnumerable<IFilterService<Name>> filters;
public MediaController(IEnumerable<IFilterService<Name>> filters)
{
this.filters = filters;
}
public async Task<HttpResponseMessage> FilterAsync(FilterType type, Name entity)
{
foreach(var filter in this.filters.Where(x => x.CanHandle(type)))
{
filter.FilterAsync(entity);
}
....
}
}
The second option is to make your interface non generic, but you keep the function generic 第二种选择是使您的接口非通用,但您保留该函数通用
public interface IFilterService
{
bool CanHandle(FilterType type);
Task<ServiceResult<T>> FilterAsync<T>(T entity);
}
public class NameService : IFilterService
{
public bool CanHandle(FacetType type)
{
return type == FacetType.Name;
}
public Task<ServiceResult<T>> FilterAsync<T>(T entity)
{
if(!entity is Name)
throw new NotSupportedException("The parameter 'entity' is not assignable to the type 'Name'");
return FilterAsyncInternal((Name)entity);
}
private async Task<ServiceResult<Name>> FilterAsyncInternal(Name entity)
{
//code
}
}
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