.net Autofac解析具有混合作用域的组件

我在asp.net中使用Autofac 2.5，我遇到了一个问题，即生命周期范围组件作为单实例组件的依赖项得到解决，从而破坏了我的线程安全。这是注册中的一个问题，但我认为Autofac将此视为违反，并将抛出异常

    private class A{}

    private class B
    {
        public B(A a){}
    }

    [Test]
    [ExpectedException()]
    public void SingleInstanceCannotResolveLifetimeDependency()
    {
        var builder = new ContainerBuilder();
        builder.RegisterType<A>()
            .InstancePerLifetimeScope();
        builder.RegisterType<B>()
            .SingleInstance();

        using (var container = builder.Build())
        {
            using (var lifetime = container.BeginLifetimeScope())
            {
                //should throw an exception
                //because B is scoped singleton but A is only scoped for the lifetime
                var b = lifetime.Resolve<B>();
            }
        }
    }

---

是-您需要命名子作用域，并将组件

A

与之显式关联。否则，正如您所观察到的，将在根（容器）范围中创建一个

实例

谢谢，我花了一段时间才弄明白单个实例只是根生命周期范围。我用一个小的扩展方法更新了我的问题，为这些情况抛出了一个异常。如果在ResolveOperation上公开“\u activationStack”会更好，那么我可以抛出更多有用的信息。
    public static class NoLifetimeResolutionAtRootScopeExtensions
{
    /// <summary>
    /// Prevents instances that are lifetime registration from being resolved in the root scope
    /// </summary>
    public static void NoLifetimeResolutionAtRootScope(this IContainer container)
    {
        LifetimeScopeBeginning(null, new LifetimeScopeBeginningEventArgs(container));
    }

    private static void LifetimeScopeBeginning(object sender, LifetimeScopeBeginningEventArgs e)
    {
        e.LifetimeScope.ResolveOperationBeginning += ResolveOperationBeginning;
        e.LifetimeScope.ChildLifetimeScopeBeginning += LifetimeScopeBeginning;
    }

    private static void ResolveOperationBeginning(object sender, ResolveOperationBeginningEventArgs e)
    {
        e.ResolveOperation.InstanceLookupBeginning += InstanceLookupBeginning;
    }

    private static void InstanceLookupBeginning(object sender, InstanceLookupBeginningEventArgs e)
    {
        var registration = e.InstanceLookup.ComponentRegistration;
        var activationScope = e.InstanceLookup.ActivationScope;

        if (registration.Ownership != InstanceOwnership.ExternallyOwned
            && registration.Sharing == InstanceSharing.Shared
            && !(registration.Lifetime is RootScopeLifetime)
            && activationScope.Tag.Equals("root"))
        {
            //would be really nice to be able to get a resolution stack here
            throw new DependencyResolutionException(string.Format(
                "Cannot resolve a lifetime instance of {0} at the root scope.", registration.Target))
        }
    }
}

container.NoLifetimeResolutionAtRootScope();

// Replace `A` registration with:
builder.RegisterType<A>().InstancePerMatchingLifetimeScope("child");

// Replace scope creation with:
using (var lifetime = container.BeginLifetimeScope("child")) {