在使用setExactAndAllowWhileIdle方法设置Alarm时，可能会遇到只触发一次的问题。这是因为该方法使用Doze模式，系统会限制Alarm触发的次数。解决方法是使用AlarmManager的setRepeating方法设置循环Alarm，然后在AlarmReceiver中重新设置Alarm使其可以继续触发。以下是示例代码：

// 设置Alarm
AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
Intent intent = new Intent(this, AlarmReceiver.class);
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent, 0);
long triggerTime = System.currentTimeMillis() + 60 * 1000; //1分钟后触发
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, triggerTime, pendingIntent);
} else {
    alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, triggerTime, 60 * 1000, pendingIntent);
}

// AlarmReceiver中重新设置Alarm
public class AlarmReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // 每次触发Alarm重新设置Alarm
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        Intent alarmIntent = new Intent(context, AlarmReceiver.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, alarmIntent, 0);
        long triggerTime = System.currentTimeMillis() + 60 * 1000; //1分钟后触发
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP, triggerTime, pendingIntent);
        } else {
            alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, triggerTime, 60 * 1000, pendingIntent);
        }
    }
}