IHttpModule 中AcquireRequestState下使用Session报未将对象设置引用到实例

public class UserAuthorizationModule : IHttpModule

    {

        public void Dispose() { }

        public void Init(HttpApplication context)

        {

            context.AcquireRequestState += new EventHandler(Application_AcquireRequestState);

        }



        public void Application_AcquireRequestState(object sender, EventArgs e)

        {

            HttpApplication application = sender as HttpApplication;;

            //HttpContext context = application.Context;

            HttpResponse response = application.Context.Response;

            Sys_Users Use = new Sys_Users();

            //获取当前请求的虚拟路径

            string Url = application.Context.Request.Path.ToString();



            switch (Url) 

            {

                case "/Web/index.htm":

                case "/Web/main.htm":

                case "/Web/menu.htm":

                case "/Web/header.htm":

                    if (application.Context.Session["Session_User"] == null)

                    {

                        application.Context.Response.Redirect("login.htm");

                        return;

                    }

                    break;

            }            

        }

    }

为什么在if (application.Context.Session["Session_User"] == null)这句的时候报未将对象设置引用到实例
------解决方案--------------------
再继承下这个接口试试：I