C# Autofac：使用Web API 2进行设置，我缺少什么

我正在一个孤立的C#解决方案中测试Autofac，我想在家庭控制器中插入一个测试管理器，它的设置如下：

非常简单的界面

public interface ITestManager
{
    IEnumerable<string> Get();
}

[MissingMethodException: No parameterless constructor defined for this object.]
   System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0
   System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +119
   System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +232
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +83
   System.Activator.CreateInstance(Type type) +11
   System.Web.Mvc.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) +55

[InvalidOperationException: An error occurred when trying to create a controller of type 'AutofacWebApi.Controllers.HomeController'. Make sure that the controller has a parameterless public constructor.]
   System.Web.Mvc.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) +178
   System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(RequestContext requestContext, Type controllerType) +76
   System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName) +88
   System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory) +191
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +50
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

并且依赖项是这样设置的

public static class Autofac
{
    public static void Register(HttpConfiguration config)
    {
        // Base set-up
        var builder = new ContainerBuilder();

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

        // OPTIONAL: Register the Autofac filter provider.
        builder.RegisterWebApiFilterProvider(config);

        // Register dependencies

        SetUpRegistration(builder);

        // Build registration.
        var container = builder.Build();

        // Set the dependency resolver to be Autofac.
        config.DependencyResolver = new AutofacWebApiDependencyResolver(container);
    }

    private static void SetUpRegistration(ContainerBuilder builder)
    {
        builder.RegisterType<TestManager>()
            .As<ITestManager>()
            .InstancePerLifetimeScope();
    }
}

运行此操作将导致以下错误：

“/”应用程序中出现服务器错误

没有为此对象定义无参数构造函数

描述：在执行过程中发生未处理的异常 当前的web请求。请查看堆栈跟踪以了解更多信息 有关错误的信息及其在代码中的来源

异常详细信息：System.MissingMethodException:无参数 为此对象定义的构造函数

我错过了什么

完整堆栈跟踪：

堆栈跟踪

public interface ITestManager
{
    IEnumerable<string> Get();
}

[MissingMethodException: No parameterless constructor defined for this object.]
   System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck) +0
   System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +119
   System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark) +232
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +83
   System.Activator.CreateInstance(Type type) +11
   System.Web.Mvc.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) +55

[InvalidOperationException: An error occurred when trying to create a controller of type 'AutofacWebApi.Controllers.HomeController'. Make sure that the controller has a parameterless public constructor.]
   System.Web.Mvc.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) +178
   System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(RequestContext requestContext, Type controllerType) +76
   System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName) +88
   System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory) +191
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +50
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

---

很简单，我从HomeController复制了控制器类信息，它的类型是

controller

，而不是

ApiController

因此，正确的实施方式是：

public class TestController : ApiController
{
    private ITestManager TestManager { get; set; }

    public TestController(ITestManager testManager)
    {
        TestManager = testManager;
    }

    // GET: api/Test
    public IEnumerable<string> Get()
    {
        return this.TestManager.Get();
    }
}

公共类TestController:ApiController
{
专用ITestManager测试管理器{get；set；}
公共测试控制器（ITestManager testManager）
{
TestManager=TestManager；
}
//获取：api/测试
公共IEnumerable Get（）
{
返回这个.TestManager.Get（）；
}
}

我使用了

builder.RegisterApiControllers（Assembly.getExecutionGassembly（））

来注册控制器，但这只适用于API控制器，而且，由于我的TestController是

Controller

类型（这是核心MVC控制器类型），因此没有正确连接

如果您也希望使用（普通的旧版）MVC，您应该使用：

builder.RegisterController（Assembly.getExecutionGassembly（））

---

感谢您为我指出了正确的方向。

请告诉我完整的堆栈跟踪是什么？我已将其添加到我的问题中。该堆栈不是源自autofac，因此它在此处没有正确“连接”。ru使用owin？在哪里定义和注册了

HomeController

？因为它是堆栈跟踪中的类，所以我们也需要查看它。在我看来，您似乎正在注册api控制器，但

TestController

不是一个。您是否尝试过使用

builder.RegisterController（Assembly.getExecutionGassembly（））

。您是否有对

Autofac.Integrations.Mvc

和

Autofac.Integrations.WebApi

的dll引用？

public class TestController : ApiController
{
    private ITestManager TestManager { get; set; }

    public TestController(ITestManager testManager)
    {
        TestManager = testManager;
    }

    // GET: api/Test
    public IEnumerable<string> Get()
    {
        return this.TestManager.Get();
    }
}