Android Alarm闹钟

1，设置闹钟(只响一次)

Intent intent = new Intent(AlarmController.this, OneShotAlarm.class);
            PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this,0, intent, 0);

            Calendar calendar = Calendar.getInstance();
            calendar.setTimeInMillis(System.currentTimeMillis());
            calendar.add(Calendar.SECOND, 30);

            // Schedule the alarm!
            AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
            am.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), sender);

2,重复闹钟

Intent intent = new Intent(AlarmController.this, RepeatingAlarm.class);
            PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this,0, intent, 0);
            
            long firstTime = SystemClock.elapsedRealtime();
            firstTime += 15*1000;

            AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
            am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,firstTime, 15*1000, sender);

3，取消闹钟

Intent intent = new Intent(AlarmController.this, RepeatingAlarm.class);
            PendingIntent sender = PendingIntent.getBroadcast(AlarmController.this,0, intent, 0);
            
            AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
            am.cancel(sender);

-----------------------------------分割线----------------------------------
一：OneShotAlarm.class/RepeatingAlarm.class
另外的Activity（Activity，Service，BroadcastReceiver）

二：PendingIntent 字面意思是 挂件意图
英文解释：* A description of an Intent and target action to perform with it. 
* Instances of this class are created with {@link #getActivity},
* {@link #getBroadcast}, {@link #getService}; the returned object can be
* handed to other applications so that they can perform the action you
* described on your behalf at a later time.

PendingIntent就是一个Intent的描述，我们可以把这个描述交给别的程序，别的程序根据这个描述在后面的别的时间做你安排做的事情