private async void UpdateButtonClicked(object sender, TappedRoutedEventArgs e)
 {
     //await CurrentManager.CheckAll();
     foreach (var t in CurrentManager.CheckAll_NoWait())
     {
         await t;
     }
 }
        public async void Run(IBackgroundTaskInstance taskInstance)
        {
            SaveLog();
            //ToastsDef.SendNotification_TwoString("后台任务执行", "当前时间" + DateTime.Now.ToString());
            var deferral = taskInstance.GetDeferral();
            var TaskNow  = new UrlContentChangeCheckerManager();
            await TaskNow.Init();

            var Tasks = TaskNow.CheckAll_NoWait();

            Task.WaitAll(Tasks.ToArray());
            Debug.WriteLine("结束任务");
            //ToastsDef.SendNotification_TwoString("后台任务结束", "当前时间" + DateTime.Now.ToString());

            deferral.Complete();
        }