asp.net - 未定义无参数构造函数对象

Question

我知道这是一个重复的问题，但我找不到错误的答案。 我试图显示数据库中保存的房间列表，但出现下一个错误:

 Server Error in '/' Application.
  No parameterless constructor defined for this object.
  Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

      Exception Details: System.MissingMethodException: No parameterless constructor defined for this object.

    Source Error:

    An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

    Stack Trace:

   [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) +98
   System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache) +241
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +69
   System.Web.Mvc.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) +67

   [InvalidOperationException: An error occurred when trying to create a controller of type 'HotelProjectFinal.Controllers.RoomController'. Make sure that the controller has a parameterless public constructor.]
   System.Web.Mvc.DefaultControllerActivator.Create(RequestContext requestContext, Type controllerType) +182
   System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(RequestContext requestContext, Type controllerType) +80
   System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName) +74
   System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory) +232
   System.Web.Mvc.<>c__DisplayClass6.<BeginProcessRequest>b__2() +49
   System.Web.Mvc.<>c__DisplayClassb`1.<ProcessInApplicationTrust>b__a() +13
   System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f) +7
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +22
   System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Func`1 func) +124
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +98
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +50
  System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
     System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8969412
    System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

但是我有一个没有参数的构造函数:

 namespace HotelProjectFinal.Controllers
 {
     public class RoomController : Controller
     {
         private IRoomRepository repository;

         public RoomController(IRoomRepository roomRepository) 
         {
             repository = roomRepository;
         }

         public ViewResult List()
         {
             return View(repository.Rooms);
         }
     }
}

我的观点是:

  @model IEnumerable<HotelProjectFinal.Models.Room>

   @{
   ViewBag.Title = "List";
    }

    @foreach (var p in Model)
    {
       <div class="item">
        <h3>@p.Room_number</h3>
       @p.Room_Type
       <h4>@p.Room_Type.Price.ToString("c")</h4>
      </div>
      }

我正在使用ninject:

               public class NinjectControllerFactory : DefaultControllerFactory
            {
    private IKernel ninjectKernel;
    public NinjectControllerFactory()
    {
        ninjectKernel = new StandardKernel();
        AddBindings();
    }
    protected override IController GetControllerInstance(RequestContext requestContext,
    Type controllerType)
    {
        return controllerType == null
        ? null
        : (IController)ninjectKernel.Get(controllerType);
    }
    private void AddBindings()
    {
        ninjectKernel.Bind<IRoomRepository>().To<EFRoomRepository>();
    }
          }
            }

Answer 1

您已经有了一个 Controller 工厂，但堆栈跟踪没有提及任何有关 Ninject 的信息，这表明您忘记告诉 MVC 相关信息。

您可以通过添加一行来告诉它来解决这个问题。

但是，推荐的做法是通过 adding a NuGet reference to Ninject.MVC3 Hook Ninject 。相关的Ninject MVC3 wiki上有关于它的文档。 .