让Ninject开始工作
本文关键字：工作 开始 Ninject | 更新日期: 2023-09-27 17:53:58
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(尽管我正在运行MVC4)。我有一个在整个项目中引用的SiteSettings类，它看起来像这样:
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性对象，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，当我试图收集我需要的数据时，我的SiteSettings类总是有一个空IUnitOfWorkFactory。
我做错了什么?每件事似乎都像所有的例子所暗示的那样，但我没有得到爱。
使用Bassam Mehanni的建议，我重写了我的DataPersister类，看起来像这样:
public class DataPersister
{
private IUnitOfWorkFactory UnitOfWorkFactory;
public DataPersister(IUnitOfWorkFactory unitOfWorkFactory)
{
UnitOfWorkFactory = unitOfWorkFactory;
}
public IUnitOfWork GetUnitOfWork()
{
return UnitOfWorkFactory.GetUnitOfWork();
}
}
…当然，现在我的SiteSettings类抱怨我的无参数构造函数。我该怎么办呢?
更新2
好的，继续，我重写了我的DataPersister类，像这样:
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，像这样:
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;
}
}
}
这样不行吗?因为它没有。DataPersister类总是使用无参数构造函数调用。我的内核绑定是这样的:
private static void RegisterServices(IKernel kernel)
{
kernel.Bind<IUnitOfWork>().To<NHUnitOfWork>();
kernel.Bind<IUnitOfWorkFactory>().To<NHUnitOfWorkFactory>();
}
我还遗漏了什么吗?
在使用IoC容器时，不应该使用不依赖于静态类的静态类。相反，您应该创建一个具有单例生存期的非静态类。
- 设置sitessettings类为非静态。
- 使用构造函数注入将所有依赖项(例如IUnitOfWorkFactory)注入到sitessettings中
- 为sitessettings 创建一个单例绑定
- 获取sitessettings的实例，无论您需要使用构造函数注入访问。
的例子:
public class SiteSettings {
public SiteSettings(IUnitOfWorkFactory uowFactory) { .... }
....
}
public class INeedToAccessSiteSettings
{
public INeedToAccessSiteSettings(SiteSettings siteSettings) { .... }
}
kenrel.Bind<SiteSettings>().ToSelf().InSingletonScope();
通常ninject会将你的服务注入到构造函数或其他东西中，它不会在运行时神奇地将所有接口变成对象实例
例如:
public class MyController : Controller
{
private IServiceThatINeed _serviceThatINeed;
public MyController(IServiceThatINeed serviceThatINeed)
{
_serviceThatINeed = _serviceThatINeed;
}
}
在这种情况下，因为你注册了你的内核实例，mvc知道如何解决这个依赖，并将传递一个实现IServiceThatINeed的对象的实例(假设你告诉ninject如何解决这个依赖)。
现在可能有一个实例，你需要得到一个服务，而不需要它被注入到mvc框架的构造函数中，在这些实例中(就像你在这里)，你需要使用ServiceLocator
例如:
var myService = ServiceLocator.Current.GetInstance<IServiceThatINeed>()
要使用ServiceLocator，您需要添加对Microsoft.Practices.ServiceLocation的引用
希望有帮助!