Asp.net 具有Web Api、信号器、MVC和OWIN的Ninject

我在我的web应用程序中使用一个Ninject DI，并使用Asp.Net堆栈中的一系列技术（MVC、web Api 2、SignalR）

我已通过以下方法使DI适用于所有正在使用的技术：

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>
    internal 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)
    {
        GlobalHost.DependencyResolver = new Microsoft.AspNet.SignalR.Ninject.NinjectDependencyResolver(kernel);
        DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));

        // Binding services here
    }        
}

到我的

OwinStartup

类。Web Api的DI已停止工作

我开始搜索合适的解决方案，找到了

Ninject.Web.WebApi.OwinHost

包。因此，为了让单个内核解决所有技术的依赖关系，我做了以下更改：

在OwinStartup中：

app.UseNinjectMiddleware(NinjectWebCommon.CreateKernel);
app.UseNinjectWebApi(config);

在NinjectWebCommon中：

//[assembly: WebActivatorEx.PreApplicationStartMethod(typeof(App.TradingServer.ConfiguratorApp.App_Start.NinjectWebCommon), "Start")]
//[assembly: WebActivatorEx.ApplicationShutdownMethodAttribute(typeof(App.TradingServer.ConfiguratorApp.App_Start.NinjectWebCommon), "Stop")]

这些行被禁用，以避免两次初始化内核

这修复了Web Api的DI，但不适用于SignalR。当客户端尝试连接到集线器时，我遇到以下异常：

System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.AspNet.SignalR.PersistentConnection.ProcessNegotiationRequest(HostContext context)
   at Microsoft.AspNet.SignalR.PersistentConnection.ProcessRequest(HostContext context)
   at Microsoft.AspNet.SignalR.Hubs.HubDispatcher.ProcessRequest(HostContext context)
   at Microsoft.AspNet.SignalR.PersistentConnection.ProcessRequest(IDictionary`2 environment)
   at Microsoft.AspNet.SignalR.Owin.Middleware.HubDispatcherMiddleware.Invoke(IOwinContext context)
   at Microsoft.Owin.Infrastructure.OwinMiddlewareTransition.Invoke(IDictionary`2 environment)
   at Microsoft.Owin.Mapping.MapMiddleware.<Invoke>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at System.Web.Http.Owin.HttpMessageHandlerAdapter.<InvokeCore>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Ninject.Web.Common.OwinHost.OwinBootstrapper.<Execute>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContextStage.<RunApp>d__5.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.<DoFinalWork>d__2.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.Owin.Host.SystemWeb.Infrastructure.ErrorState.Rethrow()
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar)
   at Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.EndFinalWork(IAsyncResult ar)
   at System.Web.HttpApplication.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) | RuntimeMethodInfo.UnsafeInvokeInternal => RuntimeMethodHandle.InvokeMethod => Application.Application_Error

与此呼叫冲突：

GlobalHost.DependencyResolver = new Microsoft.AspNet.SignalR.Ninject.NinjectDependencyResolver(kernel);

因此，问题描述仅限于此。当我使用以下模式时，信号器停止工作：

public void Configuration(IAppBuilder app)
{
    HttpConfiguration config = new HttpConfiguration();
    WebApiConfig.Register(config);

    app.UseNinjectMiddleware(CreateKernel);
    app.UseNinjectWebApi(config);

    GlobalHost.HubPipeline.AddModule(new GlobalSignalRExceptionHandler());
    app.MapSignalR();
}


private static IKernel CreateKernel()
{
    var kernel = new StandardKernel();

    GlobalHost.DependencyResolver = new Microsoft.AspNet.SignalR.Ninject.NinjectDependencyResolver(kernel);
    DependencyResolver.SetResolver(new Ninject.Web.Mvc.NinjectDependencyResolver(kernel));

    return kernel;
}

但是如果我评论这句话

    //GlobalHost.DependencyResolver = new Microsoft.AspNet.SignalR.Ninject.NinjectDependencyResolver(kernel);

---

信号员又开始工作了。当然，集线器内部没有注入。

为了同时使用WebApi和Signal的依赖项解析器，您需要实现一个如下所示的类：

    public class NinjectDependencyResolver : Microsoft.AspNet.SignalR.DefaultDependencyResolver,
    System.Web.Http.Dependencies.IDependencyResolver
{
    public readonly IKernel Kernel;

    public NinjectDependencyResolver(string moduleFilePattern)
        : base()
    {
        Kernel = new StandardKernel();
        Kernel.Load(moduleFilePattern);

    }
    public override object GetService(Type serviceType)
    {
        var service = Kernel.TryGet(serviceType) ?? base.GetService(serviceType);
        return service;
    }

    public override IEnumerable<object> GetServices(Type serviceType)
    {
        IEnumerable<object> services = Kernel.GetAll(serviceType).ToList();
        if (services.IsEmpty())
        {
            services = base.GetServices(serviceType) ?? services;
        }
        return services;
    }

    public System.Web.Http.Dependencies.IDependencyScope BeginScope()
    {
        return this;
    }

    public void Dispose()
    { }
}

public void Configuration(IAppBuilder app)
{
    var dependencyResolver = new NinjectDependencyResolver("*.dll");

    var httpConfiguration = new HttpConfiguration();
    httpConfiguration.DependencyResolver = dependencyResolver;
    app.UseWebApi(httpConfiguration);

    var hubConfig = new HubConfiguration { Resolver = dependencyResolver };
    app.MapSignalR(hubConfig);
}

---

最后，我设法获得了支持OWIN管道、WebApi、MVC和signar的工作Ninject配置

当我发布这个问题的时候，我已经有了一个解决办法（在信号集线器中禁用DI），所以我决定不再在这个问题上浪费时间，继续前进

但当我尝试用我的启动类运行OWIN内存测试服务器时，发现DI不工作。调用CreateKernel方法太晚，导致创建sengleton范围中使用的对象的多个实例

在使用了不同的初始化变体之后，我让DI为OWIN测试服务器工作，它还修复了依赖信号器的解析器

解决方案：

我停止使用包Ninject.Web.Common.OwinHost和Ninject.Web.WebApi.OwinHost，因此这些调用已从我的配置方法中删除：

//app.UseNinjectMiddleware(NinjectWebCommon.CreateKernel);
//app.UseNinjectWebApi(config);

相反，我做了以下工作：

public void Configuration(IAppBuilder app)
{
    ConfigureOAuth(app);

    HttpConfiguration config = new HttpConfiguration();
    WebApiConfig.Register(config);
    app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);

    NinjectWebCommon.Start();
    config.DependencyResolver = new NinjectDependencyResolver(NinjectWebCommon.bootstrapper.Kernel);
    app.UseWebApi(config);

    app.MapSignalR();
}

public static class NinjectWebCommon 
{
    private static bool _isStarted;

    internal static readonly Bootstrapper bootstrapper = new Bootstrapper();

    /// <summary>
    /// Starts the application
    /// </summary>
    public static void Start() 
    {
        // When creating OWIN TestService instances during unit tests
        // Start() method might be called several times
        // This check ensures that Ninject kernel is initialized only once per process
        if (_isStarted)
            return;

        _isStarted = true;

        bootstrapper.Initialize(CreateKernel);
    }

    /// <summary>
    /// Creates the kernel that will manage your application.
    /// </summary>
    /// <returns>The created kernel.</returns>
    internal static IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        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)
    {
        // DI for SignalR
        GlobalHost.DependencyResolver = new Microsoft.AspNet.SignalR.Ninject.NinjectDependencyResolver(kernel);
        // DI for MVC
        DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));

        // Binding code here
        kernel.Bind<Something>().ToSelf().InSingletonScope();
    }        
}

public void配置（IAppBuilder应用程序）
{
配置OAuth（应用程序）；
HttpConfiguration config=新的HttpConfiguration（）；
WebApiConfig.Register（配置）；
app.UseCors（Microsoft.Owin.Cors.CorsOptions.AllowAll）；
NinjectWebCommon.Start（）；
config.DependencyResolver=新的NinjectDependencyResolver（NinjectWebCommon.bootstrapper.Kernel）；
app.UseWebApi（配置）；
app.mapsigner（）；
}
公共静态类NinjectWebCommon
{
已启动专用静态布尔；
内部静态只读引导程序引导程序=新引导程序（）；
/// 
///启动应用程序
/// 
公共静态void Start（）
{
//在单元测试期间创建OWIN TestService实例时
//Start（）方法可能被多次调用
//此检查确保每个进程只初始化Ninject内核一次
如果（_已开始）
返回；
_IsStart=true；
初始化（CreateKernel）；
}
/// 
///创建将管理应用程序的内核。
/// 
///创建的内核。
内部静态IKernel CreateKernel（）
{
var kernel=新的标准内核（）；
注册服务（内核）；
返回内核；
}
/// 
///在这里加载您的模块或注册您的服务！
/// 
///内核。
私有静态无效注册服务（IKernel内核）
{
//信号机用DI
GlobalHost.dependencyrolver=新的Microsoft.AspNet.signal.Ninject.ninjectdependencyrolver（内核）；
//MVC的DI
SetResolver（新的NinjectDependencyResolver（内核））；
//这里绑定代码
kernel.Bind（）.ToSelf（）.InSingletonScope（）；
}        
}

必须在依赖项注入配置之后配置Signal。因此，在OWIN启动类中，确保在设置MVC依赖项解析程序（

System.Web.MVC.DependencyResolver

）、WebApi依赖项解析程序（

System.Web.Http.GlobalConfiguration.Configuration.Configuration.DependencyResolver

）和信号依赖项解析程序后调用

app.mapsignar（）

（

Microsoft.AspNet.signal.GlobalHost.DependencyResolver

）如果信号器使用的DI容器分发多个预期为单例的特定类型的实例，则会引发堆栈跟踪。这可能是由于各种原因造成的，其中一个原因是

GlobalHost。DependencyResolver

在使用默认信号器容器后会被修改。在OWIN中，您可能需要调用

Map信号器

后期开发。例如，Nancy

app.UseNancy（o=>o.PerformPassThrough=c=>c.Request.Path.ToUpperInvariant（）.StartsWith（“/signar”））.mapsigner（）

。真是噩梦，你是怎么弄明白的！DependencyResolver.SetResolver中的DependencyResolver（新的NinjectDependencyResolver（内核））在哪里来自哪里？这与GlobalHost不同吗？这是在

System.Web.Mvc

命名空间中定义的单例。您的IsEmpty（）来自哪里？我刚才使用的是

服务.Count（）==0

，还有Dispose（）是对DefaultDependencyResolver的重写。使用从ModelValidatorProvider到NinjectDefaultModelValidatorProvider的绑定激活ModelValidatorProvider时出错检测到两个服务的构造函数之间存在周期性依赖关系。：PI喜欢此解决方案，我发现我必须去掉Ninject.Web.*才能工作。

//app.UseNinjectMiddleware(NinjectWebCommon.CreateKernel);
//app.UseNinjectWebApi(config);

public void Configuration(IAppBuilder app)
{
    ConfigureOAuth(app);

    HttpConfiguration config = new HttpConfiguration();
    WebApiConfig.Register(config);
    app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);

    NinjectWebCommon.Start();
    config.DependencyResolver = new NinjectDependencyResolver(NinjectWebCommon.bootstrapper.Kernel);
    app.UseWebApi(config);

    app.MapSignalR();
}

public static class NinjectWebCommon 
{
    private static bool _isStarted;

    internal static readonly Bootstrapper bootstrapper = new Bootstrapper();

    /// <summary>
    /// Starts the application
    /// </summary>
    public static void Start() 
    {
        // When creating OWIN TestService instances during unit tests
        // Start() method might be called several times
        // This check ensures that Ninject kernel is initialized only once per process
        if (_isStarted)
            return;

        _isStarted = true;

        bootstrapper.Initialize(CreateKernel);
    }

    /// <summary>
    /// Creates the kernel that will manage your application.
    /// </summary>
    /// <returns>The created kernel.</returns>
    internal static IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        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)
    {
        // DI for SignalR
        GlobalHost.DependencyResolver = new Microsoft.AspNet.SignalR.Ninject.NinjectDependencyResolver(kernel);
        // DI for MVC
        DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));

        // Binding code here
        kernel.Bind<Something>().ToSelf().InSingletonScope();
    }        
}