AUTOFAC-解决开放的通用类型以解决派生类型

Question

我正在尝试使用AUTOFAC注册打开的通用类型来解决

   public interface IBackGroundJobHandler<T>  where T: INotification
 {
    public Task Handle(T notification, CancellationToken cancellationToken);
   
 }

 public  abstract class EventHandler<T> : IBackGroundJobHandler<T> where T : INotification
{
    public abstract Task Handle(T notification, CancellationToken cancellationToken);
}



 public class TestEventHandler : EventHandler<TestEvent>
{
    public async override Task Handle(TestEvent notification, CancellationToken 
     cancellationToken)
    {
        await Task.Delay(20000);
        System.Diagnostics.Debug.WriteLine("Test Event Finished");

    }
}

 public class SomeService<T> where T:INotfication
{
   public SomeService(IBackGroundJobHandler<T> handler)
  {
       //sometask
  }
 }

 

我尝试注册的派生类型：

        builder.RegisterGeneric(typeof(EventHandler<>)).As(typeof(IBackGroundJobHandler<>))
        .InstancePerLifetimeScope();

ibackgroundJobhandler在服务构建器中无法解决。

我还尝试了：

 builder.RegisterAssemblyTypes(typeof(EventHandler).GetTypeInfo().Assembly)    
.AsClosedTypesOf(typeof(IBackGroundJobHandler<>)).InstancePerLifetimeScope();

我是AutoFac的新手，该如何解决？

Answer 1

我避免了抽象类，并简单地使用了通用接口ibackgroundJobhandler＆lt;＆gt;

public class TestEventHandler : IBackGroundJobHandler<TestEvent>
{
   public async override Task Handle(TestEvent notification, CancellationToken 
   cancellationToken)
 {
    //Task

 }
}

在AUTOFAC容器中注册为：

builder.RegisterAssemblyTypes(typeof(IBackGroundEventHandler<>)
.GetTypeInfo().Assembly)                
.AsClosedTypesOf(typeof(IBackGroundEventHandler<>))
.InstancePerLifetimeScope()
.AsImplementedInterfaces();

Answer 2

EventHandler＆lt; t＆gt;是一个抽象类，因此AUTOFAC解析器无论如何都无法创建。

您尚未注册testeventhandler（例如），因此AutoFac不了解它。

当您要求ibackgroundJobhandler＆lt; testevent＆gt;我假设您想解决一个testeventhandler，但是尚未注册该课程。

因此，鉴于您需要注册testeventhandler，您可能不需要eventhandler＆lt; t＆gt;无论如何，抽象类。 （我猜您认为这将是注册从EventHandler＆lt; t＆gt; in Go中派生的所有类的一种方式）。 TestEventHandler可以实现IbackgroundJobhandler＆lt; testevent＆gt;。

class TestEventHandler : IBackGroundJobHandler<TestEvent>
{
    public async Task Handle(TestEvent notification, CancellationToken cancellationToken)
    {
         // Process the Test Event
    }
}

然后使用：

builder.RegisterType<TestEventHandler>()
    .As<IBackGroundJobHandler<TestEvent>>()
    .InstancePerLifetimeScope();

如果您有很多事件处理程序，则可能会很痛苦，因此我会使用反射来找到确实实现界面的类：

// Get the assembly that contains the implementors, assuming
// they are all in the same assembly as the TestEventHandler:
Assembly assembly = typeof(TestEventHandler).Assembly;

// Get all classes from assembly that implement the required interface
Type[] classesThatImplementIBackGroundJobHandler = assembly.GetTypes()
   .Where(t => t.IsClass 
       && t.GetInterfaces().Any(i => 
           i.IsGenericType 
           && i.GetGenericTypeDefinition() == typeof(IBackGroundJobHandler<>).GetGenericTypeDefinition())).ToArray();

// Register All Types that Implement our interface
builder.RegisterTypes(classesThatImplementIBackGrounJobHandler)
    .AsImplementedInterfaces()
    .InstancePerLifetimeScope();
      
    .