public void Configure(IApplicationBuilder app, IHostingEnvironment env,IHostApplicationLifetime applicationLeftTime)

        {

            if (env.IsDevelopment())

            {

                app.UseDeveloperExceptionPage();

            }

            else

            {

                app.UseExceptionHandler("/Home/Error");

                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.

                app.UseHsts();

            }

            applicationLeftTime.ApplicationStarted.Register(() =>

            {

                //里面可以写其他逻辑

                Console.Write("ApplicationStarted");

            });

            applicationLeftTime.ApplicationStopped.Register(()=> {

                //里面可以写其他逻辑

                Console.Write("ApplicationStopped");

            });

            applicationLeftTime.ApplicationStopping.Register(() => {

                //里面可以写其他逻辑

                Console.Write("ApplicationStopping");

            });

            app.UseHttpsRedirection();

            app.UseStaticFiles();

            app.UseCookiePolicy();

            app.UseMvc(routes =>

            {

                routes.MapRoute(

                    name: "default",

                    template: "{controller=Home}/{action=Index}/{id?}");

            });

        }