Question

尝试创建类型的控制器时发生错误   'ChatBotController'。确保控制器有一个   无参数的公共构造函数。
     在
  System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create（HttpRequestMessage   请求，HttpControllerDescriptor controllerDescriptor，类型   controllerType）↵在   System.Web.Http.Controllers.HttpControllerDescriptor.CreateController（HttpRequestMessage   要求）↵   System.Web.Http.Dispatcher.HttpControllerDispatcher.d__15.MoveNext（）

当我尝试到达IFeedbackRepository时，我得到了错误的提示。当我在ChatBotController.cs中放入构造函数时，就会发生这种情况

public class ChatBotController : ApiController
{
    IFeedbackRepository _feedbackRepository;
    public ChatBotController(IFeedbackRepository feedbackRepository)
    {
        _feedbackRepository = feedbackRepository;
    }

    [HttpPost]
    public IHttpActionResult PostQuestion([FromBody]string message) //TODO: make sure that webapi will search the message in the body of the http request
    {
        throw new NotImplementedException();
    }
}

我同时使用MVC和Api，它们都在Global.asax中解析：

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();
    GlobalConfiguration.Configure(WebApiConfig.Register);
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);

    DependencyConfig.RegisterWebApiDependencies();
    DependencyConfig.RegisterMvcDependencies();
}

这是我对MVC和Api的DependencyConfig.cs：

public static void RegisterWebApiDependencies()
{
    var container = new Container();
    container.Options.DefaultScopedLifestyle = new AsyncScopedLifestyle();

    container.Register<IAnswerGenerator, PxlAnswerGenerator>(Lifestyle.Scoped);
    container.Register<ChatBotDbContext>(Lifestyle.Scoped);
    container.Register<IFeedbackRepository, FeedbackDbRepository>(Lifestyle.Scoped);

    container.Verify();

    DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));

}

public static void RegisterMvcDependencies()
{
    var container = new Container();

    container.Options.DefaultScopedLifestyle = new WebRequestLifestyle();

    container.Register<IFeedbackRepository, FeedbackDbRepository>(Lifestyle.Scoped);
    container.Register<ChatBotDbContext>(Lifestyle.Scoped);

    container.RegisterMvcControllers(Assembly.GetExecutingAssembly());

    container.Verify();

    DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));
}

我在做什么错了？

Answer 1

根据documentation of Simple-Injector，当您要为注册的WebApi部分初始化解析器时，需要调用

container.RegisterWebApiControllers(GlobalConfiguration.Configuration);
container.Verify();
DependencyResolver.SetResolver(new SimpleInjectorWebApiDependencyResolver(container));

Answer 2

我看不到您在调用container.RegisterWebApiControllers（GlobalConfiguration.Configuration）;在RegisterWebApiDependencies（）中。这是必需的。

您可能希望在此处查看用于与ASP.NET Web API和MVC集成的simpleinjector文档：

https://simpleinjector.readthedocs.io/en/latest/webapiintegration.html

此外，以上文档在application_start（）的开头具有容器/ DI设置。如果仅上述更改不起作用，则可能要尝试将以下两行放在application_start（）的开头：

DependencyConfig.RegisterWebApiDependencies（）; DependencyConfig.RegisterMvcDependencies（）;

获取参数公共构造函数错误

2 个答案: