我在跟踪之类的计时器上设置了通知，仅每 20 秒重复一次。
它在第一次迭代期间显示通知，并且日志记录显示它每 20 秒通过一次代码，但在第一次之后通知在手机上不可见。不知道为什么，有什么想法吗？
NotificationManager notificationManager = (NotificationManager)getBaseContext().getSystemService(Context.NOTIFICATION_SERVICE);
Notification notification = new Notification(R.drawable.ic_launcher, "App is running on this Phone. ", 1);
String title = "App";
Intent notificationIntent = new Intent(getBaseContext(), MyActivity.class);
// set intent so it does not start a new activity
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
PendingIntent intent2 = PendingIntent.getActivity(getBaseContext(), 0,notificationIntent, 0);
notification.setLatestEventInfo(getBaseContext(), title, "App is running on this Phone. ", intent2);
//notification.flags |= Notification.FLAG_AUTO_CANCEL;
notification.flags |= Notification.FLAG_ONGOING_EVENT;
notificationManager.notify(0, notification);
Log.e("APP_DEBUG: doNotify finished", "APP_DEBUG: doNotify finished");