Unity get Type of the service where the dependecy gets injected

问题

Is it possible to get, in Unity, the Type of the service where the dependecy gets injected?

In Ninject you can do it like this:

kernel.Bind<ILogger>().ToMethod((context) =>
{
    ILogger logger = HttpContextLoggerFactory.GetInstance();

    // Eg: MyApplication.PeopleRepository
    string memberType = context?.Request?.Target?.Member?.DeclaringType?.FullName;

    return new LoggerMemberTypeDecorator(logger, memberType);
});

How can the same thing be implemented in Unity?

Here is what i have, but i do not have access to any context

container.RegisterType<ILogger>(new InjectionFactory(u =>
{
    ILogger logger = HttpContextLoggerFactory.GetInstance();

    // how to get it?
    string memberType = "";

    return new LoggerMemberTypeDecorator(logger, memberType);
});

回答1:

You have to register your Service (whose type then gets reported to the injected dependency's constructor) with a special InjectionConstructor.

Shamelessly copying my own answer (see details here):

container.RegisterType<IInterface, Implementation>( new MyInjectionConstructor() );

internal class MyInjectionConstructor : InjectionMember
{
    public override void AddPolicies( Type serviceType, Type implementationType, string name, IPolicyList policies )
    {
        policies.Set<IConstructorSelectorPolicy>( new MyConstructorSelectorPolicy(), new NamedTypeBuildKey( implementationType, name ) );
    }
}

internal class MyConstructorSelectorPolicy : DefaultUnityConstructorSelectorPolicy
{
    protected override IDependencyResolverPolicy CreateResolver( ParameterInfo parameter )
    {
        if( parameter.ParameterType == typeof( ILogger ) )
        {
            return new LiteralValueDependencyResolverPolicy( new Logger( parameter.Member.DeclaringType ) );
        }
        return base.CreateResolver( parameter );
    }
}

来源：https://stackoverflow.com/questions/47284091/unity-get-type-of-the-service-where-the-dependecy-gets-injected

标签

ninject

unity-container