c# - 无法使用 Ninject 将依赖项注入(inject)从 Angular 服务调用的 ASP.NET Web API Controller

Question

我正在将 Ninject 与 ASP.NET MVC 4 一起使用。我正在使用存储库并希望进行构造函数注入(inject)以将存储库传递给其中一个 Controller 。

这是实现 StatTracker 接口(interface)的上下文对象 (EntityFramework):

public class StatTrackerRepository : IStatTrackerRepository
{
    private GolfStatTrackerEntities _ctx;

    public StatTrackerRepository(GolfStatTrackerEntities ctx)
    {
        _ctx = ctx;
    }

    public IQueryable<Facility> GetFacilites()
    {
        return _ctx.Facilities;
    }
}

这是我的存储库界面:

public interface IStatTrackerRepository
{ 
    IQueryable<Facility> GetFacilites();
}

然后调用我的家庭 Controller :

public class HomeController : Controller
{
    public IStatTrackerRepository _repo { get; set; }

    public HomeController(IStatTrackerRepository repo)
    {
        _repo = repo;
    }

    public ActionResult Index()
    {
        var facilities = _repo.GetFacilites().ToList();
        return View(facilities);
    }
}

页面加载正确，但是，一旦加载页面，它会立即使用调用 $http 方法的 angularjs Controller :

function facilityIndexController($scope, $http) {
    $scope.data = [];
    $http({ method: 'GET', url: '/api/facility' }).
        success(function(result) {
            angular.copy(result.data, $scope.data);
        }).error(function() {
            alert("Could not load facilities");
        });
}

...调用以下 API Controller :

public class FacilityController : ApiController
{
    public IStatTrackerRepository _repo { get; set; }
    public GolfStatTrackerEntities ctx { get; set; }

    //public FacilityController()
    //{
    //    _repo = new StatTrackerRepository(ctx);
    //}

    public FacilityController(IStatTrackerRepository repo)
    {
        _repo = repo;
    }

    public IEnumerable<Facility> Get()
    {
        var facilities = _repo.GetFacilites().ToList();
        return facilities;
    }
}

....它属于 Angular $http 调用的错误函数，因为 FacilityController(IStatTrackerRepository repo) 从未运行过。

我曾尝试使用无参数构造函数为 FacilityController() 实例化 StatTrackerRepository(ctx)，但是，当我这样做时，我得到了一个 NullReferenceException。

我的 Ninject 配置如下:

private static IKernel CreateKernel()
{
    var kernel = new StandardKernel();
    try
    {
        kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
        kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();

        RegisterServices(kernel);
        //GlobalConfiguration.Configuration.DependencyResolver =
        //    new NinjectResolver(kernel);
        return kernel;
    }
    catch
    {
        kernel.Dispose();
        throw;
    }
}


private static void RegisterServices(IKernel kernel)
{
    kernel.Bind<GolfStatTrackerEntities>().To<GolfStatTrackerEntities>().InRequestScope();
    kernel.Bind<IStatTrackerRepository>().To<StatTrackerRepository>().InRequestScope();            
}

我不确定这是否是 Ninject 的问题，或者我实现 Ninject 的方式是否存在问题。注入(inject)似乎在 Home View 的初始加载上起作用，但是，当它使用 Angular 调用 API 时，与 Ninject 断开连接。

请帮忙。

Answer 1

我们最终在我们的一个旧项目中使用了类似的配置，并意识到我们需要向我们的 MVC/WebApi 应用程序添加更多的基础结构代码:

NinjectDependencyScope.cs

using System;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Web.Http.Dependencies;
using Ninject;
using Ninject.Syntax;

namespace YourAppNameSpace
{
    public class NinjectDependencyScope : IDependencyScope
    {
        private IResolutionRoot _resolver;

        internal NinjectDependencyScope(IResolutionRoot resolver)
        {
            Contract.Assert(resolver != null);
            _resolver = resolver;
        }

        public void Dispose()
        {
            var disposable = _resolver as IDisposable;
            if (disposable != null)
            {
                disposable.Dispose();
            }

            _resolver = null;
        }

        public object GetService(Type serviceType)
        {
            if (_resolver == null)
            {
                throw new ObjectDisposedException("this", "This scope has already been disposed");
            }

            return _resolver.TryGet(serviceType);
        }

        public IEnumerable<object> GetServices(Type serviceType)
        {
            if (_resolver == null)
            {
                throw new ObjectDisposedException("this", "This scope has already been disposed");
            }

            return _resolver.GetAll(serviceType);
        }
    }
}

NinjectDependencyResolver.cs

using System.Web.Http.Dependencies;
using Ninject;

namespace YourAppNameSpace
{
    public class NinjectDependencyResolver : NinjectDependencyScope, IDependencyResolver
    {
        private readonly IKernel _kernel;

        public NinjectDependencyResolver(IKernel kernel)
            : base(kernel)
        {
            _kernel = kernel;
        }

        public IDependencyScope BeginScope()
        {
            return new NinjectDependencyScope(_kernel.BeginBlock());
        }
    }
}

然后我们将以下内容添加到 NinjectWebCommon.cs 文件中:

public static void RegisterNinject(HttpConfiguration configuration)
        {
            // Set Web API Resolver
            configuration.DependencyResolver = new NinjectDependencyResolver(Bootstrapper.Kernel);

        }

然后是Global.asax.cs文件，Application_Start方法:

NinjectWebCommon.RegisterNinject(GlobalConfiguration.Configuration);