Can't get Ninject to dispose object in Request Scope

4
votes

I can't seem to get Ninject to dispose objects in request scope in an ASP.NET MVC application with web API no matter what I do.

What I am doing:

  • Create a new ASP.NET Web Application with Visual Studio 2013. I select the MVC template and add a Web API to it (it also has ASP.NET Identity in the package by default)
  • I install Ninject.MVC5 package via nuget (install-package Ninject.MVC5)

  • I add a the following class to my application:

    public class SomeDisposable : IDisposable { public void Dispose() { System.Diagnostics.Debug.WriteLine("test"); } }

  • I add the following binding in NinjectWebCommon RegisterServices method

    kernel.Bind().ToSelf().InRequestScope();

  • I add an object of the type SomeDisposable to the Home controller

    public HomeController(SomeDisposable some) { }

  • I run the application and place a breakpoint in the HomeController constructor and the Dispose method of the SomeDisposable class. The controller receives an object (presumably from Ninject), the page loads but the Dispose method is never called.

  • At this point things are already broken but I add a Web API controller, install Ninject.WebApi packaged and repeat the experiment with the WebAPI controller and I get the same result.

I have read a bunch of questions including this one - Ninject doesn't call Dispose on objects when out of scope and the Ninject documentation https://github.com/ninject/Ninject.Web.Common/wiki/InRequestScope and they both indicate that due to the fact that Ninject.Web.Common includes a registration for the OnePerRequestHttpModule (yes it is there) the disposal should just work but it doesn't. I also tried adding the PerRequest module in the web.config and got an error saying that I can't have this section in integrated mode.

At this point I am lost. I suspect either integrated mode or OWIN have something to do with this but I have no idea how to debug it or what to do to fix it. Any suggestions?

1
c#asp.netasp.net-mvcasp.net-web-apininject
This happened to me a while ago, make sure that you have all of the latest versions of Ninject's dependencies. The one that provides functionality for determining request scope has a bug that holds onto the objects much longer than needed and is fixed in a later version. Apologies for being vague, I can't remember the relevant names/versions. – Steve Lillis
Some people also reported issues with updating - whereas after updating .InRequestScope() didn't work anymore, at all. AFAIR Removing and reinstalling all packages in the right sequence was the key.. but don't ask me which sequence ;o – BatteryBackupUnit
I find it absurd that I can't get it to work on an empty project without changing anything from the default configuration. – Stilgar

1 Answers

7
votes

The object not being disposed was a problem in Ninject.Web.Common before version 3.2.2, as discussed here: InRequestScope is failing to dispose objects

As you have been installing Ninject via nuget, you probably installed the oldest supported dependencies. This can be avoided by using:

Install-Packages Ninject.MVC5 -DependencyVersion Highest

Please verify that you are using the current version of all Ninject packages.