是否有可能在autofac中注册一个开放的通用委托？ [英] Is it possible to register an open generic delegate in autofac?

问题描述

我想注册一个可以在运行时自行解决的泛型委托，但是我找不到在泛型上做到这一点的方法。

给定一个看起来像这样的委托：

  public delegate TOutput Pipe   

给出一个离散注册的委托，如下所示：

  public class AnonymousPipe< TInput，TOutput> 
 {
 public Pipe< TInput，TOutput> GetPipe（IContext上下文）
 {...} 
  

我想注册一个函数这个行：

  builder.RegisterGeneric（typeof（Pipe<，>））。As（ctx => 
 {
 var typeArray = ctx.RequestedType.GetGenericArguments（）; 
 //这可以被记忆
 var pipeDefinition = ctx.Resolve（typeof（AnonymousPipe<，>）。MakeGenericType （typeArray））; 
 
 return pipeDefinition.GetPipe（ctx）; 
  

我无法找到在Autofac中提供通用实现作为参数的方法 - 我可能只是缺少一些东西，我知道我可以通过一个通用的对象或接口来实现，但我想坚持一个委托的轻松。它使得单元测试在注入这些元素时变得非常简单。

有什么想法？我现在必须做离散注册（每个类型组合一个，没有泛型）。

解决方案

我可以o只需拿出注册源解决方案（Autofac中的通用锤子）。

  class PipeSource：IRegistrationSource 
 {
 public bool IsAdapterForIndividualComponents {get {return true; }} 
 
 public IEnumerable< IComponentRegistration> RegistrationsFor（
 Service service，
 Func< Service，IEnumerable< IComponentRegistration>> registrationAccessor）
 {
 var swt = service as IServiceWithType; 
 if（swt == null ||！swt.ServiceType.IsGenericType）
 yield break; 
 
 var def = swt.ServiceType.GetGenericTypeDefinition（）; 
 if（def！= typeof（Pipe<，>））
 yield break; 
 
 var anonPipeService = swt.ChangeType（
 typeof（AnonymousPipe<，>）。MakeGenericType（
 swt.ServiceType.GetGenericArguments（）））; 
 
 var getPipeMethod = anonPipeService.ServiceType.GetMethod（GetPipe）; 
 
 foreach（registerAccessor（anonPipeService）中的var anonPipeReg）
 {
 yield return RegistrationBuilder.ForDelegate（（c，p）=> {
 var anon = c .ResolveComponent（anonPipeReg，p）; 
 return getPipeMethod.Invoke（anon，null）;}）
 .As（service）
 .Targeting（anonPipeReg）
 .CreateRegistration（） ; 
} 
} 
} 
  

然后：

  builder.RegisterSource（new PipeSource（））; 
  

现在，我确定我无法输入该代码进入一个网页并让它实际编译和运行，但它可能会接近：）

I want to register a generic delegate that resolves itself at runtime, but I cannot find a way to do this on generics.

Given a delegate that looks like this:

public delegate TOutput Pipe<in TInput, out TOutput>(TInput input);

And given a discretely registered delegate that look like this:

public class AnonymousPipe<TInput, TOutput>
{
   public Pipe<TInput, TOutput> GetPipe(IContext context)
   {...}

I want to register a function along the lines of this:

builder.RegisterGeneric(typeof(Pipe<,>)).As(ctx => 
{
   var typeArray = ctx.RequestedType.GetGenericArguments();
   // this can be memoized 
   var pipeDefinition = ctx.Resolve(typeof(AnonymousPipe<,>).MakeGenericType(typeArray));

   return pipeDefinition.GetPipe(ctx);

I cannot find a way to provide an implementation of the generic as a parameter in Autofac - I may just be missing something. I know I can do this through a generic object or interface, but I want to stick with the lightness of a delegate. It makes unit testing super simple on the injection of these.

Any thoughts? I am having to do discrete registrations at the moment(one per type combination and no generics).

解决方案

I can only come up with the registration source solution (the universal hammer in Autofac.)

class PipeSource : IRegistrationSource
{
    public bool IsAdapterForIndividualComponents { get { return true; } }

    public IEnumerable<IComponentRegistration> RegistrationsFor(
        Service service,
        Func<Service, IEnumerable<IComponentRegistration>> registrationAccessor)
    {
        var swt = service as IServiceWithType;
        if (swt == null || !swt.ServiceType.IsGenericType)
            yield break;

        var def = swt.ServiceType.GetGenericTypeDefinition();
        if (def != typeof(Pipe<,>))
            yield break;

        var anonPipeService = swt.ChangeType(
            typeof(AnonymousPipe<,>).MakeGenericType(
                swt.ServiceType.GetGenericArguments()));

        var getPipeMethod = anonPipeService.ServiceType.GetMethod("GetPipe");

        foreach (var anonPipeReg in registrationAccessor(anonPipeService))
        {
            yield return RegistrationBuilder.ForDelegate((c, p) => {
                    var anon = c.ResolveComponent(anonPipeReg, p);
                    return getPipeMethod.Invoke(anon, null); })
                .As(service)
                .Targeting(anonPipeReg)
                .CreateRegistration();
        }
    }
}

Then:

builder.RegisterSource(new PipeSource());

Now, I'm certain that I can't type that code into a web page and have it actually compile and run, but it might come close :)

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