Question

我正在尝试在ActionFilterAttribute中访问以下服务。

IFooService 服务

 public interface IFooService<T>
 {
     List<T> GetFoos { get; set; }
 }

实施* FooService **

public class FooService : IFooService<int>
{
    public List<int> GetFoos()
    {
       //do something interesting here.
           return new List<int>();
    }
}

上述服务在aspnetcore依赖容器中注册为：

services.AddScoped<IFooService<int>, FooService>();

我想在我的属性中使用IFooService。但是，在属性级别，我不知道类型参数。

是否可以在不知道类型参数的情况下在ActionFilterAttribute中找到上述服务？我希望只能在界面上调用GetFoos方法。

//这是我的尝试。

 public class FooActionFilter : ActionFilterAttribute
 {
      public override void OnActionExecuted(ActionExecutedContext context)
      {
            //error here generic service require 1 argument. But i don't know how to pass this argument..
            var foo = (IFooService) context.HttpContext.RequestServices.GetService(typeof(IFooService<>));                                    
      }
 }

Answer 1

您可以将操作过滤器中的类型存储为参数。

[AttributeUsage(AttributeTargets.Method)]
public class FooActionFilterAttribute : ActionFilterAttribute
{
    public FooActionFilterAttribute(Type serviceType)
    {
        ServiceType = serviceType;
    }

    public Type ServiceType { get; }

    public override void OnActionExecuted(ActionExecutedContext context)
    {
        var service =  context.HttpContext.RequestServices.GetService(ServiceType) as FooService;                   
    }
}

// usage
[FooActionFilter(typeof(IFilterService<int>))]
public IActionResult ActionMethod()
{
}

aspnet核心mvc访问依赖性在ActionFilterAttribute内部引发服务

1 个答案: