c# - Autofac 的 None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder'

Question

尽管我以非常相似的方式使用它一年多了，但我还是回到了 Autofac 问题上，我真的需要一些建议。

我选择通过属性选择加入。这次的不同之处在于，其中一个注册使用 IIndex 根据 LoginState 枚举为手头的任务选择最合适的接口(interface)。该值通过属性提供。

您可以认为它是一个非常基本的基于 Autofac 的状态机。

由于选择加入的性质，我有以下扩展方法，它通过属性的存在和属性的值获取类型:

public static class ContainerBuilderEnumerateAttributedTypes
{
    #region EnumerateAttributedTypes(builder, action)

    [DebuggerStepThrough]
    public static void EnumerateAttributedTypes<TAttribute>(this ContainerBuilder builder,
        Action<Type, TAttribute> action) where TAttribute : Attribute
    {
        var typesAndAttributes = Assembly
            .GetExecutingAssembly()
            .GetTypes()
            .Where(type => type.GetCustomAttributes<TAttribute>(false).Any())
            .Select(type => new { Type = type, Attribute = type.GetCustomAttributes<TAttribute>(false).First() });

        foreach (var typeAndAtttribute in typesAndAttributes)
        {
            action(typeAndAtttribute.Type, typeAndAtttribute.Attribute);
        }
    }

    #endregion

    #region EnumerateAttributedTypes(builder, inherit, action)

    [DebuggerStepThrough]
    public static void EnumerateAttributedTypes<TAttribute>(this ContainerBuilder builder,
        bool inherit, Action<Type, TAttribute> action) where TAttribute : Attribute
    {
        var typesAndAttributes = Assembly
            .GetExecutingAssembly()
            .GetTypes()
            .Where(type => type.GetCustomAttributes<TAttribute>(inherit).Any())
            .Select(type => new { Type = type, Attribute = type.GetCustomAttributes<TAttribute>(inherit).First() });

        foreach (var typeAndAtttribute in typesAndAttributes)
        {
            action(typeAndAtttribute.Type, typeAndAtttribute.Attribute);
        }
    }

    #endregion
}

在 Global.asax.cs 期间，我调用了 builder.RegisterModule，它在术语中调用了 builder.RegisterModule。

在那里我有以下内容:

public class LogicAutofacModule : Module
{
    #region Load

    protected override void Load(ContainerBuilder builder)
    {
        builder.EnumerateAttributedTypes<DispatcherAttribute>((type, attribute) =>
        {
            var @interface = type.GetInterfaces().First();

            //  ReSharper disable once ConvertToLambdaExpression
            builder
                .RegisterType(type)
                .As(@interface);
        });

        builder.EnumerateAttributedTypes<LogicAttribute>((type, attribute) =>
        {
            var @interface = type.GetInterfaces().First();

            //  ReSharper disable once ConvertToLambdaExpression
            builder
                .RegisterType(type)
                .Keyed(attribute.State, @interface)
                .As(@interface);
        });
    }

    #endregion

IDispatcher 有两个实例:

IIndex<LoginState, ILogic<AuthenticateContext, AuthenticateResult>>

和

IIndex<LoginState, ILogic<AuthenticateIncurringChargeContext, AuthenticateIncurringChargeResult>> _handlers; 

LoginState 如果通过属性指定，适用时通过

[LogicDispatcher(LogicState.InvalidCredentials)]

和类似的。

无论我如何做到这一点，即使回到最基本的注册方式，我也会得到“找不到构造函数”

Autofac.Core.Activators.Reflection.DefaultConstructorFinder error message.

以前从未遇到过...请告知或询问更多信息。

事后思考...这里是 ILogic 实现的示例:

[Logic(LoginState.InvalidAccount)]
public class AuthenticateInvalidAccount : ILogic<AuthenticateContext, AuthenticateResult>
{
    #region Execute

    public AuthenticateResult Execute(AuthenticateContext context, LoginResponse response)
    {
        return new AuthenticateResult
        {
            State = State.InvalidAccount
        };
    }

    #endregion
}

还有一个调度器的实例:

[Dispatcher]
public class AuthenticateDispatcher : IDispatcher<AuthenticateContext, AuthenticateResult>
{
    #region Fields

    private readonly IIndex<LoginState, ILogic<AuthenticateContext, AuthenticateResult>> _handlers; 

    #endregion

    #region Constructors

    public AuthenticateDispatcher(IIndex<LoginState, ILogic<AuthenticateContext, AuthenticateResult>> handlers)
    {
        _handlers = handlers;
    }

    #endregion

    #region Dispatch

    public AuthenticateResult Dispatch(AuthenticateContext context)
    {
        var service = new AccountServiceClient();

        var response = service.Invoke(client => client.Login(context.Username, context.Password));

        var logic = _handlers[response.LoginState];

        var result = logic.Execute(context, response);

        return result;
    }

    #endregion
}

服务 super 简单:

[ErrorHandled]
public class Service : IService
{
    #region Fields

    private readonly IDispatcher<AuthenticateContext, AuthenticateResult> _authenticateDispatcher;

    private readonly IDispatcher<AuthenticateIncurringChargeContext, AuthenticateIncurringChargeResult> _authenticateIncurringChargeDispatcher;

    #endregion

    #region Constructor

    public Service(
        IDispatcher<AuthenticateContext, AuthenticateResult> authenticateDispatcher,
        IDispatcher<AuthenticateIncurringChargeContext, AuthenticateIncurringChargeResult> authenticateIncurringChargeDispatcher)
    {
        _authenticateDispatcher = authenticateDispatcher;
        _authenticateIncurringChargeDispatcher = authenticateIncurringChargeDispatcher;
    }

    #endregion

    #region Authenticate

    public AuthenticateResponse Authenticate(AuthenticateRequest request)
    {
        var context = request.Map<AuthenticateContext>();

        var result = _authenticateDispatcher.Dispatch(context);

        var response = result.Map<AuthenticateResponse>();

        return response;
        throw new NotImplementedException();
    }

    #endregion

    #region AuthenticateIncurringCharge

    public AuthenticateIncurringChargeResponse AuthenticateIncurringCharge(AuthenticateIncurringChargeRequest request)
    {
        //var context = request.Map<AuthenticateIncurringChargeContext>();

        //var result = _authenticateIncurringChargeDispatcher.Dispatch(context);

        //var response = result.Map<AuthenticateIncurringChargeResponse>();

        //return response;
        throw new NotImplementedException();
    }

    #endregion
}

Answer 1

比较尴尬。注释掉注册逻辑服务的代码。惭愧:(

希望有人发现扩展方法有用!