如何指示Ninject从其隐式绑定列表中隐藏一个类型

Question

Ninject是否具有可用于修饰类或构造函数以使Ninject忽略它的属性？

我需要摆脱的：

两个 服务构造之间检测到循环依赖。

这是我的代码：

// Abstraction 
public interface ICommandHandler<TCommand> 
{ 
    void Handle(TCommand command); 
} 

// Implementation 
public class ShipOrderCommandHandler 
    : ICommandHandler<ShipOrderCommand> 
{ 
    private readonly IRepository<Order> repository; 

    public ShipOrderCommandHandler(
     IRepository<Order> repository) 
    { 
     this.repository = repository; 
    } 

    public void Handle(ShipOrderCommand command) 
    { 
     // do some useful stuf with the command and repository. 
    } 
} 

我一般装饰：

public TransactionalCommandHandlerDecorator<TCommand> 
    : ICommandHandler<TCommand> 
{ 
    private ICommandHandler<TCommand> decoratedHandler; 

    public TransactionalCommandHandlerDecorator(
     ICommandHandler<TCommand> decoratedHandler) 
    { 
     this.decoratedHandler = decoratedHandler; 
    } 

    public void Handle(TCommand command) 
    { 
     using (var scope = new TransactionScope()) 
     { 
      this.decoratedHandler.Handle(command); 
      scope.Complete(); 
     } 
    } 
} 

我的容器注册：

kernel.Bind(typeof(ICommandHandler<>)) 
    .To(typeof(TransactionCommandHandlerDecora‌​tor<>)); 

Answer 1

你应该能够使用Contextual Binding到Bind的带有const的原始接口使他们只能在正确的背景下考虑（即，当他们进入装饰者时）。

我有一个非常相似的这样的When扩展名，如果你仍然在看，那么明天我可以粘贴到这里。

编辑：代码，我脑子里想的（原来它没有做想要直接）

public static class NinjectWhenExtensions 
{ 
    public static void WhenRootRequestIsFor<T>(this IBindingSyntax that) 
    { 
     that.BindingConfiguration.Condition = request => request.RootRequestIsFor<T>(); 
    } 
} 

public static class NinjectRequestExtensions 
{ 
    public static bool RootRequestIsFor<T>(this IRequest request) 
    { 
#if false 
     // Need to use ContextPreservingGet in factories and nested requests for this to work. 
     // http://www.planetgeek.ch/2010/12/08/ninject-extension-contextpreservation-explained/ 
     return RootRequest(request).Service == typeof(T); 
#else 
     // Hack - check the template arg is the interface wer'e looking for rather than doing what the name of the method would actually suggest 
     IRequest rootRequest = RootRequest(request); 
     return rootRequest.Service.IsGenericType && rootRequest.Service.GetGenericArguments().Single() == typeof(T); 
#endif 
    } 

    static IRequest RootRequest(IRequest request) 
    { 
     if (request.ParentRequest == null) 
      return request; 

     return RootRequest(request.ParentRequest); 
    } 
} 

用于连接装饰： -

root.Bind<IEndpointSettings>().To<IAnonymousEndpointSettings>().WhenRootRequestIsFor<IAnonymousService>(); 
root.Bind<IEndpointSettings>().To<IAuthenticatedSettings>().WhenRootRequestIsFor<IServiceA>(); 

编辑2：你应该能够使用创建一个When衍生物，除了当它被Resolved馈送到装饰者时，该衍生物从图片中取得IX的通用绑定。然后，Decorator的Bind可以使用上下文保留（@Remo上有一篇文章）来确保进入上下文，以便您的谓词可以决定，或者您可以将元数据添加到请求中，并让When依赖于。

所以，我想： 1.阅读上下文保存 2.检查/转储进入你的When条件上的要求方面的内容，并确定如何可以适当过滤。

（并希望有人会用一个罐头内衬答案一起去！）

上下文保存扩展可能需要扮演一个角色。

Answer 2

这是一个基于您的代码的工作示例。

public class AutoDecorationFacts 
{ 
    readonly StandardKernel _kernel = new StandardKernel(); 

    public AutoDecorationFacts() 
    { 
     _kernel.Bind(typeof(ICommandHandler<>)) 
      .To(typeof(TransactionalCommandHandlerDecorator<>)) 
      .Named("decorated"); 
    } 

    [Fact] 
    public void RawBind() 
    { 
     _kernel.Bind(typeof(ICommandHandler<>)).To<ShipOrderCommandHandler>().WhenAnyAnchestorNamed("decorated"); 
     VerifyBoundRight(); 
    } 

    void VerifyBoundRight() 
    { 
     var cmd = _kernel.Get<ICommandHandler<ShipOrderCommand>>(); 
     Assert.IsType<TransactionalCommandHandlerDecorator<ShipOrderCommand>>(cmd); 
    } 

最佳效果Ninject.Extensions.Conventions使用： -

[Fact] 
    public void NameSpaceBasedConvention() 
    { 
     _kernel.Bind(scan => scan 
      .FromThisAssembly() 
      .SelectAllClasses() 
      .InNamespaceOf<CommandHandlers.ShipOrderCommandHandler>() 
      .BindAllInterfaces() 
      .Configure(x => x.WhenAnyAnchestorNamed("decorated"))); 
     VerifyBoundRight(); 
    } 

    [Fact] 
    public void UnconstrainedWorksTooButDontDoThat() 
    { 
     _kernel.Bind(scan => scan 
      .FromThisAssembly() 
      .SelectAllClasses() 
      .BindAllInterfaces() 
      .Configure(x=>x.WhenAnyAnchestorNamed("decorated"))); 
     VerifyBoundRight(); 
    } 
} 

你的类：

公共类ShipOrderCommand { }

// Abstraction 
public interface ICommandHandler<TCommand> 
{ 
    void Handle(TCommand command); 
} 

// Implementation 
namespace CommandHandlers 
{ 
    public class ShipOrderCommandHandler 
     : ICommandHandler<ShipOrderCommand> 
    { 
     public ShipOrderCommandHandler(
      ) 
     { 
     } 

     public void Handle(ShipOrderCommand command) 
     { 
      // do some useful stuf with the command and repository. 
     } 
    } 
} 
public class TransactionalCommandHandlerDecorator<TCommand> 
    : ICommandHandler<TCommand> 
{ 
    private ICommandHandler<TCommand> decoratedHandler; 

    public TransactionalCommandHandlerDecorator(
     ICommandHandler<TCommand> decoratedHandler) 
    { 
     this.decoratedHandler = decoratedHandler; 
    } 

    public void Handle(TCommand command) 
    { 
     this.decoratedHandler.Handle(command); 
    } 
} 

（使用的NuGet - 最新Ninject的版本和Ninject.Extensions.Conventions）