web api 2中autofac的无参数构造函数错误

Question

我使用 Autofac 作为 IOC，这是我的结构：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AdTudent.Repo
{
    public interface IRepository
    {
        IAdvertisementRepository Advertisements { get; set; }
        IProfileRepository Profiles { get; set; }
    }
}

我的存储库类是：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AdTudent.Repo
{
    public class Repositories : IRepository
    {
        public Repositories(IAdvertisementRepository advertisementRepository,
                            IProfileRepository profileRepository)
        {
            Advertisements = advertisementRepository;
            Profiles = profileRepository;
        }
        public IAdvertisementRepository Advertisements { get; set; }
        public IProfileRepository Profiles { get; set; }
    }
}

而我的创业班是：

public partial class Startup
{
    public void Configuration(IAppBuilder app)
    {
         var builder = new ContainerBuilder();

        builder.RegisterType<Repositories>().As<IRepository>();
        builder.Register<IGraphClient>(context =>
        {
            var graphClient = new GraphClient(new Uri("http://localhost:7474/db/data"));
            graphClient.Connect();
            return graphClient;
        }).SingleInstance();
        // STANDARD WEB API SETUP:

        // Get your HttpConfiguration. In OWIN, you'll create one
        // rather than using GlobalConfiguration.
        var config = new HttpConfiguration();

        // Register your Web API controllers.
        //builder.RegisterApiControllers(Assembly.GetExecutingAssembly());

        // Run other optional steps, like registering filters,
        // per-controller-type services, etc., then set the dependency resolver
        // to be Autofac.
       
        var container = builder.Build();
        config.DependencyResolver = new AutofacWebApiDependencyResolver(container);

        app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);

        // OWIN WEB API SETUP:

        // Register the Autofac middleware FIRST, then the Autofac Web API middleware,
        // and finally the standard Web API middleware.
        app.UseAutofacMiddleware(container);
        app.UseAutofacWebApi(config);
        app.UseWebApi(config);

        ConfigureAuth(app);
    }
}
    

这是我的帐户管理员：

public class AccountController : ApiController
{
    private  IRepository _repository;
    private const string LocalLoginProvider = "Local";
    private ApplicationUserManager _userManager;
    private IGraphClient _graphClient;
   

    public ISecureDataFormat<AuthenticationTicket> AccessTokenFormat { get; private set; }       

    public AccountController(IRepository repository, IGraphClient graphClient,
         ISecureDataFormat<AuthenticationTicket> accessTokenFormat)
    {
        
        AccessTokenFormat = accessTokenFormat;
        _repository = repository;
        _graphClient = graphClient;

    }
}

但我总是这个问题

"Message": "An error has occurred.",
"ExceptionMessage": "An error occurred when trying to create a controller of type 'AccountController'. Make sure that the controller has a parameterless public constructor.",
"ExceptionType": "System.InvalidOperationException",
"StackTrace": "   at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)\r\n   at System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage request)\r\n   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()

我在互联网上搜索，但找不到任何可以帮助的信息，有人可以指导我吗？

Answer 1

根据WebApi OWIN documentation：

OWIN 集成中的一个常见错误是使用GlobalConfiguration.Configuration。 在 OWIN 中，您从头开始创建配置。在使用 OWIN 集成时，您不应在任何地方引用 GlobalConfiguration.Configuration。

您似乎有几个问题：

1. 使用 OWIN 时需要更新 HttpConfiguration。
2. 您缺少UseAutofacWebApi 虚拟方法调用。

根据文档，您还需要 Autofac WebApi OWIN package。

public class Startup
{
    public void Configuration(IAppBuilder app)
    {
        var builder = new ContainerBuilder();

        // STANDARD WEB API SETUP:

        // Get your HttpConfiguration. In OWIN, you'll create one
        // rather than using GlobalConfiguration.
        var config = new HttpConfiguration();

        // Register your Web API controllers.
        builder.RegisterApiControllers(Assembly.GetExecutingAssembly());

        // Run other optional steps, like registering filters,
        // per-controller-type services, etc., then set the dependency resolver
        // to be Autofac.
        var container = builder.Build();
        config.DependencyResolver = new AutofacWebApiDependencyResolver(container);

        app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);

        // OWIN WEB API SETUP:

        // Register the Autofac middleware FIRST, then the Autofac Web API middleware,
        // and finally the standard Web API middleware.
        app.UseAutofacMiddleware(container);
        app.UseAutofacWebApi(config);
        app.UseWebApi(config);
    }
}

Answer 2

检查您的 Global.asax.cs。如果有，则应删除此行：

GlobalConfiguration.Configure(WebApiConfig.Register);

您可以像这样将其移至 Startup.cs 配置：

WebApiConfig.Register(config);

Answer 3

您还没有告诉 Autofac 如何创建 ISecureDataFormat<AuthenticationTicket> 实例。

在您致电 builder.Build() 之前将其添加到您的启动课程中。

builder.RegisterType<ISecureDataFormat<AuthenticationTicket>>().As<TicketDataFormat>();