如何检查 AlarmManager 是否已经设置了警报? [英] How to check if AlarmManager already has an alarm set?

问题描述

当我的应用程序启动时，我希望它检查某个特定的警报(通过 AlarmManager 注册)是否已经设置并正在运行.谷歌的结果似乎表明没有办法做到这一点.这仍然正确吗?我需要执行此检查，以便在采取任何操作来创建新警报之前向用户提供建议.

When my app starts, I want it to check if a particular alarm (registered via AlarmManager) is already set and running. Results from google seem to indicate that there is no way to do this. Is this still correct? I need to do this check in order to advise the user before any action is taken to create a new alarm.

推荐答案

根据 ron 发布的评论，这里是详细的解决方案.假设您已经注册了一个重复的警报，具有如下待处理的意图:

Following up on the comment ron posted, here is the detailed solution. Let's say you have registered a repeating alarm with a pending intent like this:

Intent intent = new Intent("com.my.package.MY_UNIQUE_ACTION");
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, 
                                      intent, PendingIntent.FLAG_UPDATE_CURRENT);
Calendar calendar = Calendar.getInstance();
calendar.setTimeInMillis(System.currentTimeMillis());
calendar.add(Calendar.MINUTE, 1);

AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 1000 * 60, pendingIntent);

检查它是否处于活动状态的方法是:

The way you would check to see if it is active is to:

boolean alarmUp = (PendingIntent.getBroadcast(context, 0, 
        new Intent("com.my.package.MY_UNIQUE_ACTION"), 
        PendingIntent.FLAG_NO_CREATE) != null);

if (alarmUp)
{
    Log.d("myTag", "Alarm is already active");
}

这里的关键是 FLAG_NO_CREATE ，如 javadoc 中所述:如果描述的 PendingIntent **does not** 已经存在，那么只需返回 null(而不是创建一个新的)

The key here is the FLAG_NO_CREATE which as described in the javadoc: if the described PendingIntent **does not** already exists, then simply return null (instead of creating a new one)

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