asp.net mvc 2应用程序中的IoC和dataContext配置

Question

我有 Global.asax 就像下面的代码：

public class MvcApplication : System.Web.HttpApplication
{
    public static void RegisterRoutes(RouteCollection routes)
    {
    // ....
    }

    protected void Application_Start()
    {
    AreaRegistration.RegisterAllAreas();

    RegisterRoutes(RouteTable.Routes);

    ControllerBuilder.Current.SetControllerFactory(typeof(IOCControllerFactory));
    }
}

public class IOCControllerFactory : DefaultControllerFactory
{
    private readonly IKernel kernel;

    public IOCControllerFactory()
    {
        kernel = new StandardKernel(new NanocrmContainer());
    }

    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
    {
        if (controllerType == null)
            return base.GetControllerInstance(requestContext, controllerType);

        var controller = kernel.TryGet(controllerType) as IController;

        if (controller == null)
            return base.GetControllerInstance(requestContext, controllerType);

        var standartController = controller as Controller;

        if (standartController is IIoCController)
            ((IIoCController)standartController).SetIoc(kernel);

        return standartController;
    }

    class NanocrmContainer : Ninject.Modules.NinjectModule
    {
        public override void Load()
        {
            // ...

            Bind<DomainModel.Entities.db>().ToSelf().InRequestScope().WithConstructorArgument("connection", "Data Source=lims;Initial Catalog=nanocrm;Persist Security Info=True;User ID=***;Password=***");
        }
    }
}

在这种情况下，如果在某个地方它是类，定义如下：

public class UserRepository : IUserRepository
{
    private db dataContext;
    private IUserGroupRepository userGroupRepository;

    public UserRepository(db dataContext, IUserGroupRepository userGroupRepository)
    {
        this.dataContext = dataContext;
        this.userGroupRepository = userGroupRepository;
    }
}

然后创建 dataContext 实例（如果没有创建）在此请求范围内）由 Ninject 提供。

所以现在的麻烦是 - 在哪里调用 dataContext 方法 .Dispose()？

UPD：

所以我听从了KeeperOfTheSoul的建议并以这种方式解决了这个问题：

    public override void ReleaseController(IController controller)
    {
        base.ReleaseController(controller);

        var db = kernel.Get<DomainModel.Entities.db>();
        db.Dispose();
    }

Answer 1

处理此问题的好地方是 IControllerFactory.ReleaseController，例如

public override void ReleaseController() {
    base.ReleaseController();
    //Do whatever you need to clean up the IoC container here
}

在 NInject 中，这可以通过使用 激活块，在创建控制器时请求开始时您可以将激活块存储在HttpContext的当前项中，在ReleaseController期间您可以检索之前创建的激活块并将其丢弃。

您还可以考虑使用 InScope 并让自定义范围实现 INotifyWhenDispose。之后的用法与激活块相同，只不过现在您将范围存储在 HttpContext 的当前项中。

Answer 2

有时用于处置数据库连接的一种模式是从终结器调用Dispose。

public class db : IDisposable {
   //called by the garbage collector 
   ~db() {
     //Call dispose to make sure the resources are cleaned up
     Dispose(false);
   }

   //IDisposable implementation
   public void Dispose() {
     Dispose(true);
   }
   //subclasses of db can override Dispose(bool) and clean up their own fields
   protected virtual void Dispose (bool disposing) {
     if (disposing) {
       //Supress finalization as all resources are released by this method
       //Calling Dispose on IDisposable members should be done here
       GC.SupressFinalize();
     }
     //Clean up unmanaged resources
     //Do not call other objects as they might be already collected if called from the finalizer
   }
}

Answer 3

您可以将其挂接到 Application_EndRequest 中。