/// <summary>
 /// 单例启动后台任务
 /// </summary>
 /// <returns></returns>
 public static BackgroundTasks Create()
 {
     lock (_lock)
     {
         if (_backgroundtask == null)
             _backgroundtask = new BackgroundTasks();
         return _backgroundtask;
     }
 }
        protected void Application_Start()
        {
            AreaRegistration.RegisterAllAreas();

            WebApiConfig.Register(GlobalConfiguration.Configuration);
            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            //BundleConfig.RegisterBundles(BundleTable.Bundles);
            _backgroundtask = BackgroundTasks.Create();
        }