Question

说明我有一个HttpRequestScoped的旧版类型和一个使用该服务的旧版Web服务。为了解决传统问题中的服务，我有一个全局解析器。这在1.4中运行良好，现在我正在使用2.1.12我遇到DependencyResolutionException。

代码在2.1.12中，我的Global.asax.cs：

builder.Register(c => new SomeLegacyType(HttpContext.Current)) // note: it relies on HttpContext.Current
.As<SomeLegacyType>()
.HttpRequestScoped();

_containerProvider = new ContainerProvider(builder.Build()); // this is my app's IContainerProvider
Setup.Resolver = new AutofacResolver(_containerProvider.ApplicationContainer);

Setup.Resolver是一个单例，它被设置为AutofacResolver，如下所示：

public class AutofacResolver : IResolver
{
    private readonly IContainer _container;

    public AutofacResolver(IContainer container)
    {
        _container = container;
    }

    public TService Get<TService>()
    {
        return _container.Resolve<TService>();
    }
}

Web服务如下所示：

[WebService]
public LegacyWebService : WebService
{
   [WebMethod(EnableSession=true)]
   public String SomeMethod() 
   {
      var legacyType = Setup.Resolver.Get<SomeLegacyType>();
   }
}

异常调用Setup.Resolver.Get<SomeLegacyType>()时出现以下异常：

Autofac.Core.DependencyResolutionException: No scope matching the expression 'value(Autofac.Builder.RegistrationBuilder`3+<>c__DisplayClass0[SomeAssembly.SomeLegacyType,Autofac.Builder.SimpleActivatorData,Autofac.Builder.SingleRegistrationStyle]).lifetimeScopeTag.Equals(scope.Tag)' is visible from the scope in which the instance was requested. 
at Autofac.Core.Lifetime.MatchingScopeLifetime.FindScope(ISharingLifetimeScope mostNestedVisibleScope)
   at Autofac.Core.Resolving.ComponentActivation..ctor(IComponentRegistration registration, IResolveOperation context, ISharingLifetimeScope mostNestedVisibleScope)
   at Autofac.Core.Resolving.ResolveOperation.Resolve(ISharingLifetimeScope activationScope, IComponentRegistration registration, IEnumerable`1 parameters)
   at Autofac.Core.Lifetime.LifetimeScope.Resolve(IComponentRegistration registration, IEnumerable`1 parameters)
   at Autofac.Core.Container.Resolve(IComponentRegistration registration, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.TryResolve(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance)
   at Autofac.ResolutionExtensions.Resolve(IComponentContext context, Service service, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.Resolve[TService](IComponentContext context)

附带问题是否有更好的方法在ASMX中注入属性，就像注入ASPX页面一样（而不是使用Setup.Resolver）？由于遗留问题，我使用AttributedInjectionModule。该模块似乎不适用于ASMX。

Answer 1

如果您将“解析器”配置为使用RequestLifetime而不是ApplicationContainer，则所有应该按预期工作。

这意味着您的IContainer参数必须更改为ILifetimeScope。

我不确定注入ASMX依赖项的更好方法，可能有一个，但我不认为Autofac支持它。

使用Autofac 2.1.12解决ASMX中的HttpRequestScoped服务

1 个答案: