当用户从最近的应用程序列表中删除应用程序时，如何取消警报管理器警报？

Question

As per a comment in this question : "Standard Android only allows you to remove things from that list on Android 3.0+, and doing so does not affect your AlarmManager events".

I would like to cancel the alarms if the user swipes the app from list of recent apps, but there seems to be no way we can handle the swiping of app from recent apps list where the alarm could be canceled. I have option in the app for the user to cancel the alarm which executes this code :

public static void cancelAlarm() {
        if (alarmUp())
        {
            alarmMgr.cancel(pendingIntent);
        }
  }
  public static boolean alarmUp() {
      return (pendingIntent != null);
  }

But how to cancel the alarm when the app removed forcibly ? I do not want to cancel the alarm when app is closed (by pressing back or home button).

Answer 1

Two steps needed to accomplish this:

1. Detect the app removal from the recents list. See What Exactly Happens When You Swipe An Android App From the Recent Apps List? . That's the best info I found on the subject.

2. Cancel the alarm. Your question assumes that the pendingIntent variable still holds an intent constructed earlier. This won't work in an activity that was unloaded. Instead, construct an intent that's "equal to" the original intent ("their action, data, type, class, and categories are the same"), and cancel that one.

Answer 2

这可以通过在Activity OnDestroy()中调用alarm.cancel()轻松实现。