在 Global.asax 中创建全局 Ninject 内核答案

【问题标题】：Creating global Ninject kernel in Global.asax在 Global.asax 中创建全局 Ninject 内核
【发布时间】：2016-05-23 08:51:02
【问题描述】：

我想在 Application_BeginRequest() 方法中访问 Ninject Kernel。所以我在HttpContext.Current.Items中设置了Ker nel。

   public class WebApiApplication : HttpApplication
    {
        public IKernel Kernel
        {
            get { return (IKernel) HttpContext.Current.Items["Context"]; }
            set { HttpContext.Current.Items["Context"] = value; }
        }

        protected void Application_Start()
        {
            .....

            Kernel = new StandardKernel();

            GlobalConfiguration.Configuration.DependencyResolver = 
                         new NinjectDependencyResolver(Kernel);

            Debug.WriteLine("Application started with kernel: {0}", Kernel);
        }

        protected void Application_BeginRequest()
        {
            Debug.WriteLine("Application begin request with kernel: {0}", Kernel);
        }

我启动应用程序，但内核对象在 Application_BeginRequest() 方法中为空。

【问题讨论】：

标签： c# asp.net-web-api ninject ninject.web.mvc

【解决方案1】：

HttpContext.Current.Items 是特定于请求的。因此，它们会为每个请求重新创建。为了能够在请求中访问Kernel，您需要在Application_BeginRequest 中基于每个请求进行设置：

public class WebApiApplication : HttpApplication
{
    private static Kernel globalKernel;

    public static IKernel Kernel
    {
        get { return (IKernel) HttpContext.Current.Items["Context"]; }
        set { HttpContext.Current.Items["Context"] = value; }
    }

    protected void Application_Start()
    {
        .....

        globalKernel = new StandardKernel();

        GlobalConfiguration.Configuration.DependencyResolver = 
                     new NinjectDependencyResolver(globalKernel);

        Debug.WriteLine("Application started with kernel: {0}", globalKernel);
    }

    protected void Application_BeginRequest()
    {
        // This adds the Kernel to the items collection that is specific to the request
        Kernel = globalKernel;
        Debug.WriteLine("Application begin request with kernel: {0}", Kernel);
    }

【讨论】：