Specify entity framework context implement IDisposable with Ninject

Question

I am implementing context in my service as per code below. I need to setup IDisposable correctly as it is not being called.

public class MyWidgetService : WidgetService, IDisposable
{
    private bool _disposed;
    private readonly DBContext _context;

    public MyWidgetService()
    {
        _context = new DBContext();
    }

    public List GetWidgets()
    {
            return _context.stuff().ToList();
    }

    // however dipose is never being called
    public void Dispose()
    {
        Dispose(true);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (!_disposed)
        {
            if (disposing)
            {
                _context.Dispose();
            }
        }
        _disposed = true;
    }
}

I am then using Ninject to serve instances of my widget service

public SomeClass(IWidgetService widgetService)
{         
    _widgetService = widgetService;            
}

I register the widget service with ninject here

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<IWidgtetService>().To<WidgetService>();
                kernel.Bind<IWidgetService>().To<WidgetService>();                

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

Please share the code where you register that `MyWidgetService` should be substituted when an `IWidgetService` is needed. For Ninject, I believe this should be registered `PerRequest` in order to make the IoC dispose of it. — danludwig, Feb 13 '15 at 14:42
@Pod don't tell us how you register using a comment. Instead, update your question. — danludwig, Feb 13 '15 at 14:48
Try this instead: `kernel.Bind().To().InRequestScope();` <-- that should cause it to be disposed at the end of a web request. — danludwig, Feb 13 '15 at 15:04
OK thanks that is interesting. So how would I change my service? Do I need not to implement IDisposable? — Pod, Feb 13 '15 at 15:06

score 0 · Accepted Answer · edited May 23 '17 at 12:12

See the answer to this question:

Guidelines For Dispose() and Ninject

From the post:

Ninject disposes every Disposable object that has another scope other than InTransientScope as soon as the scope object to which the created object is tied is collected by GC. That's why every Disposable object should be Bindd with a scope that is not InTransientScope(). E.g. you can use InParentScope() from the NamedScope extension which will Dispose the object as soon as the object it is injected into is garbage collected.

You are not specifying a scope on your bindings, so they are using transient scope by default. If you use any other scope, you should see Dispose get called.

Thanks Jim yes I see what you mean now – Pod Feb 13 '15 at 18:43 — Pod, Feb 13 '15 at 18:43

Specify entity framework context implement IDisposable with Ninject

1 Answers1