让Ninject工作

时间:2013-01-17 23:25:36

标签: c# asp.net-mvc asp.net-mvc-4 ninject ninject-extensions

显然,我错过了一些东西。我有一个MVC应用程序并安装了Ninject 3和MVC3扩展(虽然我正在运行MVC4)。我有一个SiteSettings类,在整个项目中引用,如下所示:

public class SiteSettings
{
    private static readonly Common.Logging.ILog Logger = Common.Logging.LogManager.GetCurrentClassLogger();
    private static ObservableDictionary<string, string> settings;
    private static bool Initialized = false;
    private static DataPersister persister;

    public static void Initialize()
    {
        if (Initialized) throw new InvalidOperationException("The SiteSettings object has already been initialized.");
        persister = new DataPersister();
        using (var u = persister.UnitOfWorkFactory.GetUnitOfWork())
        {
            var settingsList = u.SiteSettings.GetAll();
            settings = new ObservableDictionary<string, string>(settingsList.ToDictionary(key => key.SiteSettingName, value => value.SiteSettingValue));
            settings.OnChange += new kvpChangeEvent<string, string>(settings_OnChange);
        }
        Initialized = true;
    }

    static void settings_OnChange(object sender, odKVPChangeEventArgs<string, string> e)
    {
        using (var u = persister.UnitOfWorkFactory.GetUnitOfWork())
        {
            var setting = u.SiteSettings.GetByName(e.Key);
            setting.SiteSettingValue = e.Value;
            u.SiteSettings.Update(setting);
            u.Save();
            Logger.Info(i => i("Changed the '{0}' site setting from '{1}' to '{2}'.", e.Key, e.OldValue, e.Value));
        }
    }

    private static int _ItemsPerPage;
    public static int ItemsPerPage
    {
        get
        {
            return _ItemsPerPage;
        }
        set
        {
            _ItemsPerPage = value;
            settings["itemsPerPage"] = value.ToString();
        }
    }

    private static int _SessionLifeInMinutes;
    public static int SessionLifeInMinutes
    {
        get
        {
            return _SessionLifeInMinutes;
        }
        set
        {
            _SessionLifeInMinutes = value;
            settings["sessionLifeInMinutes"] = value.ToString();
        }
    }

    private static string _DateFormat;
    public static string DateFormat
    {
        get
        {
            return _DateFormat;
        }
        set
        {
            _DateFormat = value;
            settings["defaultDateFormat"] = value;
        }
    }
}

我构建了一个数据持久化对象,如下所示:

public class DataPersister
{
    public IUnitOfWorkFactory UnitOfWorkFactory { get; set; }
}

...我的NinjectWebCommon.cs看起来像这样:

public static class NinjectWebCommon
{
    private static readonly Bootstrapper bootstrapper = new Bootstrapper();

    /// <summary>
    /// Starts the application
    /// </summary>
    public static void Start()
    {
        DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
        DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
        bootstrapper.Initialize(CreateKernel);
    }

    /// <summary>
    /// Stops the application.
    /// </summary>
    public static void Stop()
    {
        bootstrapper.ShutDown();
    }

    /// <summary>
    /// Creates the kernel that will manage your application.
    /// </summary>
    /// <returns>The created kernel.</returns>
    private static IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
        kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();

        RegisterServices(kernel);
        return kernel;
    }

    /// <summary>
    /// Load your modules or register your services here!
    /// </summary>
    /// <param name="kernel">The kernel.</param>
    private static void RegisterServices(IKernel kernel)
    {
        kernel.Bind<IUnitOfWork>().To<NHUnitOfWork>();
        kernel.Bind<IUnitOfWorkFactory>().To<NHUnitOfWorkFactory>();
    }
}

在我看来,我已经满足了我对依赖注入的所有要求。我的Global.asax.cs Application_Start()看起来像这样:

protected void Application_Start()
{
    ViewEngines.Engines.Clear();
    ViewEngines.Engines.Add(new MonoRazorViewEngine());

    AreaRegistration.RegisterAllAreas();
    RegisterGlobalFilters(GlobalFilters.Filters);
    RegisterRoutes(RouteTable.Routes);
    ControllerBuilder.Current.DefaultNamespaces.Add("MyApplication.Application.Controllers");
    Initialize.Security();
    SiteSettings.Initialize();
}

...然而,当我尝试收集所需的数据时,我的SiteSettings类始终为空IUnitOfWorkFactory

我做错了什么?似乎所有的例子都应该如此,但我没有爱。

更新

使用Bassam Mehanni的建议,我重写了我的DataPersister课程,看起来像这样:

public class DataPersister
{
    private IUnitOfWorkFactory UnitOfWorkFactory;
    public DataPersister(IUnitOfWorkFactory unitOfWorkFactory)
    {
        UnitOfWorkFactory = unitOfWorkFactory;
    }
    public IUnitOfWork GetUnitOfWork()
    {
        return UnitOfWorkFactory.GetUnitOfWork();
    }
}

...但当然现在我的SiteSettings类抱怨我的无参数构造函数。我该怎么办?

更新2

好的,继续,我重写了我的DataPersister课程,如下:

public class DataPersister
{
    private static readonly Common.Logging.ILog Logger = Common.Logging.LogManager.GetCurrentClassLogger();

    private IUnitOfWorkFactory UnitOfWorkFactory { get; set; }
    public IUnitOfWork GetUnitOfWork()
    {
        return UnitOfWorkFactory.GetUnitOfWork();
    }
    [Inject]
    public DataPersister(IUnitOfWorkFactory factory)
    {
        Logger.Info("Injected constructor called");
        UnitOfWorkFactory = factory;
    }
    public DataPersister()
    {
        Logger.Info("Parameterless constructor called");
    }
}

然后我重写了我的SiteSettings类,如下:

public class SiteSettings
{
    private static readonly Common.Logging.ILog Logger = Common.Logging.LogManager.GetCurrentClassLogger();
    private ObservableDictionary<string, string> settings;
    private DataPersister persister;
    private SiteSettings()
    {
        persister = new DataPersister();
        using (var u = persister.GetUnitOfWork())
        {
            var settingsList = u.SiteSettings.GetAll();
            settings = new ObservableDictionary<string, string>(settingsList.ToDictionary(key => key.SiteSettingName, value => value.SiteSettingValue));
            settings.OnChange += new kvpChangeEvent<string, string>(settings_OnChange);
        }
    }
    private static SiteSettings instance;

    public static SiteSettings Instance
    {
        get
        {
            if (instance == null)
            {
                instance = new SiteSettings();
            }
            return instance;
        }
    }

    private void settings_OnChange(object sender, odKVPChangeEventArgs<string, string> e)
    {
        using (var u = persister.GetUnitOfWork())
        {
            var setting = u.SiteSettings.GetByName(e.Key);
            setting.SiteSettingValue = e.Value;
            u.SiteSettings.Update(setting);
            u.Save();
            Logger.Info(i => i("Changed the '{0}' site setting from '{1}' to '{2}'.", e.Key, e.OldValue, e.Value));
        }
    }

    private int _ItemsPerPage;
    public int ItemsPerPage
    {
        get
        {
            return _ItemsPerPage;
        }
        set
        {
            _ItemsPerPage = value;
            settings["itemsPerPage"] = value.ToString();
        }
    }

    private int _SessionLifeInMinutes;
    public int SessionLifeInMinutes
    {
        get
        {
            return _SessionLifeInMinutes;
        }
        set
        {
            _SessionLifeInMinutes = value;
            settings["sessionLifeInMinutes"] = value.ToString();
        }
    }

    private string _DateFormat;
    public string DateFormat
    {
        get
        {
            return _DateFormat;
        }
        set
        {
            _DateFormat = value;
            settings["defaultDateFormat"] = value;
        }
    }
}

不应该这样吗?因为它没有。始终使用无参数构造函数调用DataPersister类。我的内核绑定如下所示:

private static void RegisterServices(IKernel kernel)
{
    kernel.Bind<IUnitOfWork>().To<NHUnitOfWork>();
    kernel.Bind<IUnitOfWorkFactory>().To<NHUnitOfWorkFactory>();
}

我还缺少其他东西吗?这变得非常令人沮丧。

1 个答案:

答案 0 :(得分:3)

通常ninject会在构造函数或其他东西中注入你的服务,它不会在运行时神奇地将所有接口转换为对象实例

e.g:

public class MyController : Controller
{
   private IServiceThatINeed _serviceThatINeed;
   public MyController(IServiceThatINeed serviceThatINeed)
   { 
       _serviceThatINeed = _serviceThatINeed;
   }
}

在这种情况下,由于您注册了内核实例,因此mvc知道如何解决此依赖关系,并将传递实现IServiceThatINeed的对象的实例(假设您告诉ninject如何解决此依赖关系。

现在可能有一个实例,你需要获得一个服务,而不是由mvc框架在构造函数中注入,在这些实例中(就像你在这里的那个),你需要使用ServiceLocator

e.g:

var myService = ServiceLocator.Current.GetInstance<IServiceThatINeed>()

要使用ServiceLocator,您需要添加对Microsoft.Practices.ServiceLocation

的引用

希望有所帮助!