Android开发之实现对闹钟Alarm的控制

随着可穿戴及其他一些辅助设备的出现，在这些设备上实现对Android手机的控制就有了需求，如下图。

Android 闹钟应用是在packages/apps/DeskClock下面，查看相关代码发现，闹钟响起的时候会启动一个叫AlarmActivity的类，而这个类注册Receiver来接受广播。

action字符串的定义：

 // AlarmActivity listens for this broadcast intent, so that other applications
 // can snooze the alarm (after ALARM_ALERT_ACTION and before ALARM_DONE_ACTION).
  //小睡操作
 public static final String ALARM_SNOOZE_ACTION = "com.android.deskclock.ALARM_SNOOZE";

 // AlarmActivity listens for this broadcast intent, so that other applications
 // can dismiss the alarm (after ALARM_ALERT_ACTION and before ALARM_DONE_ACTION).
 //蓝牙关闭操作
 public static final String ALARM_DISMISS_ACTION = "com.android.deskclock.ALARM_DISMISS";

receiver的注册：

 IntentFilter filter = new IntentFilter(AlarmService.ALARM_DONE_ACTION);
 filter.addAction(ALARM_SNOOZE_ACTION);
 filter.addAction(ALARM_DISMISS_ACTION);
 registerReceiver(mReceiver, filter);

Receiver的处理动作：

 private BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
             String action = intent.getAction();
             Log.v("AlarmActivity - Broadcast Receiver - " + action);
             if (action.equals(ALARM_SNOOZE_ACTION)) {
                 snooze();
             } else if (action.equals(ALARM_DISMISS_ACTION)) {
                 dismiss();
             } else if (action.equals(AlarmService.ALARM_DONE_ACTION)) {
                 finish();
             } else {
                 Log.i("Unknown broadcast in AlarmActivity: " + action);
             }
         }
     };

发送相应广播就可以实现闹钟的Snooze和Dismiss。

那可穿戴设备如何获取手机上闹钟的状态呢？ 其实也是通过接受广播来实现：

 // A public action send by AlarmService when the alarm has started.
 public static final String ALARM_ALERT_ACTION = "com.android.deskclock.ALARM_ALERT";

 // A public action sent by AlarmService when the alarm has stopped for any reason.
 //手机被操作
 public static final String ALARM_DONE_ACTION = "com.android.deskclock.ALARM_DONE";

上面第一条是闹钟响起，第二条就是闹钟被操作。 注册相应的Receiver即可。