Question

我开始在我的MVC5代码优先应用程序中使用Ninject。这是我的NinjectWebCommon.cs：

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

            kernel.Bind<CMSContext>()
                .ToSelf()
                //.InSingletonScope();
                .InRequestScope();

            kernel.Bind<IExecutiveRepository>()
                .To<ExecutiveRepository>();

            kernel.Bind<IExecutiveSectionRepository>()
                .To<ExecutiveSectionRepository>();

            kernel.Bind<IExecutiveSectionMappingRepository>()
                .To<ExecutiveSectionMappingRepository>();

            kernel.Bind<IUserRepository>()
                .To<UserRepository>();

            kernel.Bind<IContentRepository>()
                .To<ContentRepository>();

            RegisterServices(kernel);
            return kernel;
        }
        catch
        {
            kernel.Dispose();
            throw;
        }
    }

我尝试了.InSingletonScope（）以及.InRequestScope（），但我仍然得到了IEntityChangeTracker的多个实例＆＃39; 实体对象。错误。这是我的界面：

public interface IExecutiveRepository : IDisposable { IEnumerable<Executive> GetExecutives(); Executive GetExecutiveById(int executiveId); void InsertExecutive(Executive executive); void UpdateExecutive(Executive executive); void DeleteExecutive(int executiveId); void Save(); }

这是我的具体内容：

public class ExecutiveRepository : IExecutiveRepository, IDisposable { private CMSContext context; public ExecutiveRepository(CMSContext context) { this.context = context; } public IEnumerable<Executive> GetExecutives() { return context.Executives.ToList(); } public Executive GetExecutiveById(int id) { return context.Executives.Find(id); } public void InsertExecutive(Executive executive) { context.Executives.Add(executive); } public void DeleteExecutive(int executiveId) { Executive executive = context.Executives.Find(executiveId); context.Executives.Remove(executive); } public void UpdateExecutive(Executive executive) { context.Entry(executive).State = EntityState.Modified; } public void Save() { context.SaveChanges(); } private bool disposed = false; protected virtual void Dispose(bool disposing) { if (!this.disposed) { if (disposing) { context.Dispose(); } } this.disposed = true; } public void Dispose() { Dispose(true); GC.SuppressFinalize(this); } }

这是控制器（顶部相关部分）：

public class ExecutiveController : Controller { private IExecutiveRepository executiveRepository; private IUserRepository userRepository; private IExecutiveSectionRepository executiveSectionRepository; private IExecutiveSectionMappingRepository executiveSectionMappingRepository; private IContentRepository contentRepository; private Ninject.IKernel _kernel = new StandardKernel(); //[Inject] public ExecutiveController() { executiveRepository = _kernel.Get<ExecutiveRepository>(); userRepository = _kernel.Get<UserRepository>(); executiveSectionRepository = _kernel.Get<ExecutiveSectionRepository>(); executiveSectionMappingRepository = _kernel.Get<ExecutiveSectionMappingRepository>(); contentRepository = _kernel.Get<ContentRepository>(); } ...

不确定我做错了什么，但是在添加了一个新的＆＃39; Executive＆＃39;它是炸弹......我确实理解它试图使用单独的上下文而这是问题，但我不知道如何解决它。显然，NinjectWebCommon.cs类中的行：

kernel.Bind<CMSContext>() .ToSelf() //.InSingletonScope(); .InRequestScope();

应该是修复，但它不是...... 任何想法/建议？

Answer 1

你应该使用NUGET包Ninject.Web.Mvc，如果你还没有。这会将您的应用程序配置为使用Ninject，而不是绑定。看起来您已经从我CreateKernel()方法中看到的东西的结合方面相当熟悉了。

一旦绑定到位，就不应该在控制器中创建内核，这是因为Ninject.Web.Mvc库配置Ninject为您创建控制器。因此，您添加到它们的任何依赖项都应自动解析。

因此，您可以使用构造函数注入来解析依赖项：

public class ExecutiveController : Controller
{
    private IExecutiveRepository ExecutiveRepository;
    private IUserRepository UserRepository;
    private IExecutiveSectionRepository ExecutiveSectionRepository;
    private IExecutiveSectionMappingRepository ExecutiveSectionMappingRepository;
    private IContentRepository ContentRepository;

    public ExecutiveController(
         IExecutiveRepository executiveRepository,
         IUserRepository userRepository,
         IExecutiveSectionRepository executiveSectionRepository,
         IExecutiveSectionMappingRepository executiveSectionMappingRepository,
         IContentRepository contentRepository)
    {

         // Set the field values
         this.ExecutiveRepository = executiveRepository,
         this.UserRepository = userRepository,
         this.ExecutiveSectionRepository = executiveSectionRepository,
         this.ExecutiveSectionMappingRepository = executiveSectionMappingRepository,
         this.ContentRepository = contentRepository;
    }

    public ActionResult Index(int id)
    {
        // Use one of your dependencies...
        var executive = this.executiveRepository.GetExecutiveById(id);
    }
}

或者您可以使用具有相同效果的[Inject]属性：

public class ExecutiveController : Controller
{
    [Inject]
    public IExecutiveRepository executiveRepository { get; set; }

    [Inject]
    public IUserRepository userRepository { get; set; }

    [Inject]
    public IExecutiveSectionRepository executiveSectionRepository { get; set; }

    [Inject]
    public IExecutiveSectionMappingRepository executiveSectionMappingRepository { get; set; }

    [Inject]
    public IContentRepository contentRepository { get; set; }

    public ExecutiveController()
    {

    }

    public ActionResult Index(int id)
    {
        // Use one of your dependencies...
        var executive = this.executiveRepository.GetExecutiveById(id);
    }
}

Answer 2

您正在为每个控制器创建一个内核。

InRequestScope仅确保每个请求每个内核一个实例。

因此，您需要调整内核的设置，以便每个Web应用程序只有一个内核。参见：

Answer 3

这可能无法回答这个问题。但我倾向于使用EF为您提供的IDbContextFactory并执行以下操作：

public interface IDefaultContextFactory : IDbContextFactory<CMSContext> {}

public class DefaultContextFactory : IDefaultContextFactory 
{
    private readonly Lazy<CMSContext> lazyContext = new Lazy<CMSContext>(() => new CMSContext());

    public CMSContext Create() 
    {
        return lazyContext.Value;
    }
}

然后你只需绑定它，当你需要上下文时，你可以做这样的事情：

public class ExecutiveRepository : IExecutiveRepository, IDisposable
{
    private readonly CMSContext context;

    public ExecutiveRepository(IDefaultContextFactory contextFactory)
    {
        this.context = contextFactory.Create();
    }
}

我相信@BatteryBackupUnit是正确的，我也会考虑将上述模式用于上下文。

Ninject：IEntityChangeTracker的多个实例不能引用实体对象

3 个答案: