Autofac.如何使用自定义方法(属性)来解决一些接口？

Question

我有以下接口:

public interface IConfigurationProvider<TSettings> where TSettings : ISettings, new() 
{
       TSettings Settings { get; }
}
public interface ISettings
{
}

我有以下IConfigurationProvider实现:

public class ConfigurationProvider<TSettings> : IConfigurationProvider<TSettings> where 

    TSettings : ISettings, new()
        {
            public ConfigurationProvider() 
            {
                this.BuildConfiguration();
            }

            public TSettings Settings { get; private set; }

            private void BuildConfiguration() 
            {
                this.Settings = new TSettings();
                //...load and assign properties to 'this.Settings'
                //...skipped
                // now 'Settings' property contains configured 'ISettings' instance
            }
        }

我也可以有不同的类实现'ISettings'接口.例如,

public class UserSettings : ISettings
    {
        public int SomeProperty1 { get; set; }
        public int SomeProperty2 { get; set; }
    }


public class CatalogSettings : ISettings
    {
        public int SomeProperty3 { get; set; }
        public int SomeProperty4 { get; set; }
    }

我正在使用以下代码来配置'ContainerBuilder': builder.RegisterGeneric(typeof(ConfigurationProvider<>)).As(typeof(IConfigurationProvider<>));

它工作正常.为了获得'UserSettings',我使用以下代码:

var userSettingsProvider = builder.Resolve<IConfigurationProvider<UserSettings>>();
var userSettings = userSettingsProvider.Settings;

问题是:我应该如何配置'ContainerBuilder',以便我可以通过以下方式解决某些'ISettings':

var userSettings = builder.Resolve<UserSettings>();

Autofac有可能吗？

提前致谢

Answer 1

您可以使用IRegistrationSource- 请参阅http://nblumhardt.com/2010/01/declarative-context-adapters-autofac2/以获取概述.

基本结构如下:

class SettingsSource : IRegistrationSource {
    static readonly MethodInfo BuildMethod = typeof(SettingsSource).GetMethod(
        "BuildRegistration",
        BindingFlags.Static | BindingFlags.NonPublic);

    public IEnumerable<IComponentRegistration> RegistrationsFor(
            Service service,
            Func<Service, IEnumerable<IComponentRegistration>> registrations) {
        var ts= service as TypedService;
        if (ts != null && typeof(ISettings).IsAssignableFrom(ts.ServiceType) {
            var buildMethod = BuildMethod.MakeGenericMethod(ts.ServiceType);
            yield return (IComponentRegistration) buildMethod.Invoke(null, null);
        }
    }

    static IComponentRegistration BuildRegistration<TSettings>()
            where TSettings : ISettings {
        return RegistrationBuilder
            .ForDelegate((c, p) =>
                c.Resolve<IConfigurationProvider<TSettings>>().Settings)
            .CreateRegistration();
    }

    public bool IsAdapterForIndividualComponents { get { return false; } }
}

这样注册如下:

builder.RegisterGeneric(typeof(ConfigurationProvider<>))
    .As(typeof(IConfigurationProvider<>));
builder.RegisterSource(new SettingsSource());

(未编译或测试,如果它失败,请告诉我;))