How to integrate Ninject into ASP.NET Core 2.0 web applications?

Question

I found out that Ninject recently introduced support for the .NET Standard 2.0 / .NET Core 2.0 .

However, I can’t find any extension to actually integrate it into web applications (for example similar to Ninject.Web.Common )

If you look at the code from the old ASP.NET MVC solution, I realized that the whole mechanism is different from the classic one, based on WebActivatorEx.PreApplicationStartMethodand WebActivatorEx.ApplicationShutdownMethodAttribute, which are no longer available in the ASP.NET core.

In addition, the old assembly Ninject.Web.Commonprovided several useful classes used for initialization - Bootstrapper, OnePerRequestHttpModule, NinjectHttpModule:

public static void Start()
{
    DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
    DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
    Bootstrapper.Initialize(CreateKernel);
}

: - Ninject - ASP.NET Core 2.0?

Answer 1

:

. Ninject 4.0.0, - (). Ninject 3.3.x .

:

@Steven ASP.NET Core 2.0 Ninject ( 3.3.x, 4.0). Missing-Core-DI-Extensions Git repo, dotnetjunkie.

Ninject:

1) AspNetCoreExtensions.cs AspNetCoreMvcExtensions.cs .

2) , DI: TestService, ITestService:

public class TestService : ITestService
{
    public int Data { get; private set; }

    public TestService()
    {
        Data = 42;
    }
} 

public interface ITestService
{
    int Data { get; }
}

Ninject 3.3.x

Startup.cs, :

1)

private readonly AsyncLocal<Scope> scopeProvider = new AsyncLocal<Scope>();
private IKernel Kernel { get; set; }

private object Resolve(Type type) => Kernel.Get(type);
private object RequestScope(IContext context) => scopeProvider.Value;  

2) ConfigureServices(IServiceCollection services) ( )

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

services.AddRequestScopingMiddleware(() => scopeProvider.Value = new Scope());
services.AddCustomControllerActivation(Resolve);
services.AddCustomViewComponentActivation(Resolve);

3) Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) ( )

Kernel = RegisterApplicationComponents(app, loggerFactory);

4) :

private IKernel RegisterApplicationComponents(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
    // IKernelConfiguration config = new KernelConfiguration();
    Kernel = new StandardKernel();

    // Register application services
    foreach (var ctrlType in app.GetControllerTypes())
    {
        Kernel.Bind(ctrlType).ToSelf().InScope(RequestScope);
    }

    Kernel.Bind<ITestService>().To<TestService>().InScope(RequestScope);

    // Cross-wire required framework services
    Kernel.BindToMethod(app.GetRequestService<IViewBufferScope>);
    Kernel.Bind<ILoggerFactory>().ToConstant(loggerFactory);

    return Kernel;
}

private sealed class Scope : DisposableObject { }

5) BindToMethod

public static class BindingHelpers
{
    public static void BindToMethod<T>(this IKernel config, Func<T> method) => config.Bind<T>().ToMethod(c => method());
}

6) DI, , . Ninject (, ConfigureRequestScoping)

Ninject 4.0.0

IKernel 4, IReadOnlyKernel IKernelConfiguration ( ).

1) (IReadOnlyKernel)

private readonly AsyncLocal<Scope> scopeProvider = new AsyncLocal<Scope>();
private IReadOnlyKernel Kernel { get; set; }

private object Resolve(Type type) => Kernel.Get(type);
private object RequestScope(IContext context) => scopeProvider.Value;

2) 3)

4) :

private IReadOnlyKernel RegisterApplicationComponents(IApplicationBuilder app, ILoggerFactory loggerFactory)
{
    IKernelConfiguration config = new KernelConfiguration();

    // Register application services
    foreach (var ctrlType in app.GetControllerTypes())
    {
        config.Bind(ctrlType).ToSelf().InScope(RequestScope);
    }

    config.Bind<ITestService>().To<TestService>().InScope(RequestScope);

    // Cross-wire required framework services
    config.BindToMethod(app.GetRequestService<IViewBufferScope>);
    config.Bind<ILoggerFactory>().ToConstant(loggerFactory);

    return config.BuildReadonlyKernel();
}

5) IKernelConfiguration

public static class BindingHelpers
{
    public static void BindToMethod<T>(this IKernelConfiguration config, Func<T> method) => config.Bind<T>().ToMethod(c => method());
}