Microsoft Unity IoC 和 ASP.NET mvc4 应用程序不起作用。为什么？

Question

我正在尝试将 Unity IoC 容器设置为 ASP.NET mvc4 应用程序。 我创建了空项目并使用包管理控制台安装了下一个产品

• 安装包 Unity
• 安装包 Unity.Mvc4

一切顺利完成。但是在我运行我的应用程序后，我遇到了异常

说明：在执行当前 Web 请求期间发生未处理的异常。请查看堆栈跟踪以获取有关错误及其源自代码的位置的更多信息。 异常详细信息：System.MissingMethodException：无法创建接口实例。

这是简单的代码。 Global.asax.cs

public class MvcApplication : System.Web.HttpApplication
{
    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();

        WebApiConfig.Register(GlobalConfiguration.Configuration);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
        RouteConfig.RegisterRoutes(RouteTable.Routes);

        Bootstrapper.Initialise();
    }
}

public interface IA
{
    void test();
}
public class A : IA
{
    public A() { }
    public void test()
    {
        throw new NotImplementedException();
    }
}

HomeController.cs

public class HomeController : Controller
{
    //
    // GET: /Home/

    public ActionResult Index(IA a)
    {
        return View();
    }

}

Bootstrapper.cs：

public static class Bootstrapper
{
    public static void Initialise()
    {
        var container = BuildUnityContainer();

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

    private static IUnityContainer BuildUnityContainer()
    {
        var container = new UnityContainer();

        container.RegisterType<IA, A>();          

        return container;
    }
}

我做错了什么以及为什么代码不起作用？

堆栈跟踪：

堆栈跟踪：[MissingMethodException：无法创建接口的实例。] System.RuntimeTypeHandle.CreateInstance(RuntimeType 类型，Boolean publicOnly，Boolean noCheck，Boolean& canBeCached，RuntimeMethodHandleInternal& ctor，Boolean& bNeedSecurityCheck) +0 System.RuntimeType.CreateInstanceSlow（布尔publicOnly，布尔skipCheckThis，布尔fillCache）+98 System.RuntimeType.CreateInstanceDefaultCtor（布尔publicOnly，布尔skipVisibilityChecks，布尔skipCheckThis，布尔fillCache）+241 System.Activator.CreateInstance（类型类型，布尔非公共）+69 System.Web.Mvc.DefaultModelBinder.CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType) +199 System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +572 System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +454 System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +317 System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +117 System.Web.Mvc.Async.c_DisplayClass25.b_1e(AsyncCallback asyncCallback, Object asyncState) +476 System.Web.Mvc.Async.WrappedAsyncResult1.Begin(AsyncCallback callback, Object state, Int32 timeout) +124 System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +304 System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__17(AsyncCallback asyncCallback, Object asyncState) +30 System.Web.Mvc.Async.WrappedAsyncResult1.Begin（AsyncCallback 回调，对象状态，Int32 超时）+124 System.Web.Mvc.Controller.BeginExecuteCore（AsyncCallback 回调，对象状态）+389 System.Web.Mvc.Async.WrappedAsyncResult1.Begin(AsyncCallback callback, Object state, Int32 timeout) +124 System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +319 System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +15 System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__2(AsyncCallback asyncCallback, Object asyncState) +76 System.Web.Mvc.Async.WrappedAsyncResult1.Begin（AsyncCallback 回调，对象状态，Int32 超时）+124 System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback 回调, 对象状态) +251 System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback 回调, 对象状态) +50 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8837208 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

Answer 1

我完全不知道你的有什么问题，但这里是适合我的设置；

public static class Bootstrapper
{
    public static void Initialise()
    {
        var container = BuildUnityContainer();
        DependencyResolver.SetResolver(new UnityDependencyResolver(container));
    }

    private static IUnityContainer BuildUnityContainer()
    {
        var container = new UnityContainer();
        container.RegisterType<ICategoryRepository, CategoryRepository>(new HierarchicalLifetimeManager());
        return container;
    }
}

全球.asax

 Bootstrapper.Initialise();

现在，在我的控制器构造函数中；

ICategoryRepository _catRepo;

public CategoryController(ICategoryRepository catRepo)
{
    _catRepo = catRepo;
}
public ActionResult Index()
{
    ViewBag.CategoriesList = _catRepo.GetAllCategories();
    return View();
}