如何检查是否AlarmManager已经有一个报警设置？

问题描述

在我的应用程序开始，我希望它检查是否有特定的报警（通过AlarmManager注册）已经被设置和运行。结果来自谷歌似乎表明，有没有办法做到这一点。这仍然是正确的吗？我需要做这个检查，以提醒用户在采取任何行动之前创建一个新的警报。谢谢罗恩

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.ThanksRon

推荐答案

在Ron张贴评论跟进，这里是详细的解决方案。比方说，你已经注册了一个悬而未决的意图这样的重复报警：

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);

您会检查，看它是否有效的方法是：

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 这是在Javadoc描述：如果描述PendingIntent **不**已经存在，那么只需返回（而不是创建一个新的）空

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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