Ninject拦截具有某些属性的任何方法吗? [英] Ninject Intercept any method with certain attribute?

问题描述

如何获取Ninject.Extensions.Interception，以便基本上让我将特定的拦截器绑定到具有属性的任何方法...伪代码:

How can I get Ninject.Extensions.Interception to basically let me bind a specific interceptor to any method that has an attribute... psudocode:

Kernel.Intercept(context => context.Binding.HasAttribute<TransactionAttribute>())
      .With<TransactionInterceptor>

使用类似这样的课程:

public SomeClass
{
    [TransactionAttribute]
    public void SomeTransactedMethod()
    { /*do stuff */ }
}

推荐答案

假定您正在使用 Ninject.Extensions.Interception 这应该可以解决问题

Assuming that you are using Ninject.Extensions.Interception this should do the trick

public class TransactionInterceptor : IInterceptor
{
    public void Intercept(IInvocation invocation)
    {
        // Do something...
    }
}

public class TransactionAttribute : InterceptAttribute
{
    public override IInterceptor CreateInterceptor(IProxyRequest request)
    {
        return new TransactionInterceptor();
    }
}

public class SomeClass
{
    [Transaction]
    public virtual void SomeTransactedMethod() { }
}

确保应拦截的方法标记为虚方法.

Make sure that the method that should be intercepted is marked as virtual.

调用SomeTransactedMethod()时应将其拦截.

var kernel = new StandardKernel();
kernel.Bind<SomeClass>().ToSelf();

var someClass = kernel.Get<SomeClass>();
someClass.SomeTransactedMethod();

更新

您可以创建自定义计划策略.

You could create a custom planning strategy.

public class CustomPlanningStrategy<TAttribute, TInterceptor> :
    NinjectComponent, IPlanningStrategy
        where TAttribute : Attribute
        where TInterceptor : IInterceptor
{
    private readonly IAdviceFactory adviceFactory;
    private readonly IAdviceRegistry adviceRegistry;

    public CustomPlanningStrategy(
        IAdviceFactory adviceFactory, IAdviceRegistry adviceRegistry)
        {
            this.adviceFactory = adviceFactory;
            this.adviceRegistry = adviceRegistry;
        }

        public void Execute(IPlan plan)
        {
            var methods = GetCandidateMethods(plan.Type);
            foreach (var method in methods)
            {
                var attributes = method.GetCustomAttributes(
                    typeof(TAttribute), true) as TAttribute[];
                if (attributes.Length == 0)
                {
                    continue;
                }

                var advice = adviceFactory.Create(method);

                advice.Callback = request => request.Kernel.Get<TInterceptor>();
                adviceRegistry.Register(advice);

                if (!plan.Has<ProxyDirective>())
                {
                    plan.Add(new ProxyDirective());
                }
            }
        }
    }

    private static IEnumerable<MethodInfo> GetCandidateMethods(Type type)
    {
        var methods = type.GetMethods(
            BindingFlags.Public | 
            BindingFlags.NonPublic | 
            BindingFlags.Instance
        );

        return methods.Where(ShouldIntercept);
    }

    private static bool ShouldIntercept(MethodInfo methodInfo)
    {
        return methodInfo.DeclaringType != typeof(object) &&
               !methodInfo.IsPrivate &&
               !methodInfo.IsFinal;
    }
}

现在应该可以了.

var kernel = new StandardKernel();
kernel.Components.Add<IPlanningStrategy, 
    CustomPlanningStrategy<TransactionAttribute, TransactionInterceptor>>();

kernel.Bind<SomeClass>().ToSelf();

var someClass = kernel.Get<SomeClass>();
someClass.SomeTransactedMethod();

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