android AlarmService
分类: Android
2012-08-23 10:23
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举报 实验2:使用AlarmService:
2.1通过AlarmService每个5秒发送一个广播,setRepeating时的类型为AlarmManager.ELAPSED_REALTIME。
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
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am.setRepeating(AlarmManager.ELAPSED_REALTIME, firstTime, 5 * 1000 , sender);
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拔掉USB线,按下电源键,过一段时间再次打开屏幕,发现定时器没有继续计数。
2.2setRepeating是的类型设置为AlarmManager.ELAPSED_REALTIME_WAKEUP
AlarmManager am = (AlarmManager)getSystemService(ALARM_SERVICE);
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am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, firstTime, 5 * 1000 , sender);
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拔掉USB线,按下电源键,过一点时间再次打开屏幕,发现定时器一直在计数。
如此看来,使用WAKEUP才能保证自己想要的定时器一直工作,但是肯定会引起耗电量的增加
AlarmManager的使用机制有的称呼为全局定时器,有的称呼为闹钟。通过对它的使用,个人觉得叫全局定时器比较合适,其实它的作用和Timer有点相似。都有两种相似的用法:(1)在指定时长后执行某项操作(2)周期性的执行某项操作
AlarmManager对象配合Intent使用,可以定时的开启一个Activity,发送一个BroadCast,或者开启一个Service.
下面的代码详细的介绍了两种定时方式的使用:
(1)在指定时长后执行某项操作
Java代码
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- //操作:发送一个广播,广播接收后Toast提示定时操作完成
- Intent intent =new Intent(Main.this, alarmreceiver.class);
- intent.setAction("short");
- PendingIntent sender=
- PendingIntent.getBroadcast(Main.this, 0, intent, 0);
- //设定一个五秒后的时间
- Calendar calendar=Calendar.getInstance();
- calendar.setTimeInMillis(System.currentTimeMillis());
- calendar.add(Calendar.SECOND, 5);
- AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
- alarm.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), sender);
- //或者以下面方式简化
- //alarm.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+5*1000, sender);
- Toast.makeText(Main.this, "五秒后alarm开启", Toast.LENGTH_LONG).show();
- //操作:发送一个广播,广播接收后Toast提示定时操作完成
- Intent intent =new Intent(Main.this, alarmreceiver.class);
- intent.setAction("short");
- PendingIntent sender=
- PendingIntent.getBroadcast(Main.this, 0, intent, 0);
- //设定一个五秒后的时间
- Calendar calendar=Calendar.getInstance();
- calendar.setTimeInMillis(System.currentTimeMillis());
- calendar.add(Calendar.SECOND, 5);
- AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
- alarm.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), sender);
- //或者以下面方式简化
- //alarm.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis()+5*1000, sender);
- Toast.makeText(Main.this, "五秒后alarm开启", Toast.LENGTH_LONG).show();
Java代码
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- public static class alarmreceiver extends BroadcastReceiver{
- @Override
- public void onReceive(Context context, Intent intent) {
- // TODO Auto-generated method stub
- if(intent.getAction().equals("short")){
- Toast.makeText(context, "short alarm", Toast.LENGTH_LONG).show();
- }else{
- Toast.makeText(context, "repeating alarm",
- Toast.LENGTH_LONG).show();
- }
- }
- }
- public static class alarmreceiver extends BroadcastReceiver{
- @Override
- public void onReceive(Context context, Intent intent) {
- // TODO Auto-generated method stub
- if(intent.getAction().equals("short")){
- Toast.makeText(context, "short alarm", Toast.LENGTH_LONG).show();
- }else{
- Toast.makeText(context, "repeating alarm",
- Toast.LENGTH_LONG).show();
- }
- }
- }
Java代码
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- Intent intent =new Intent(Main.this, alarmreceiver.class);
- intent.setAction("repeating");
- PendingIntent sender=PendingIntent
- .getBroadcast(Main.this, 0, intent, 0);
- //开始时间
- long firstime=SystemClock.elapsedRealtime();
- AlarmManager am=(AlarmManager)getSystemService(ALARM_SERVICE);
- //5秒一个周期,不停的发送广播
- am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP
- , firstime, 5*1000, sender);
- Intent intent =new Intent(Main.this, alarmreceiver.class);
- intent.setAction("repeating");
- PendingIntent sender=PendingIntent
- .getBroadcast(Main.this, 0, intent, 0);
- //开始时间
- long firstime=SystemClock.elapsedRealtime();
- AlarmManager am=(AlarmManager)getSystemService(ALARM_SERVICE);
- //5秒一个周期,不停的发送广播
- am.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP
- , firstime, 5*1000, sender);
以后开始周期性的执行task;
AlarmManager的取消:(其中需要注意的是取消的Intent必须与启动Intent保持绝对一致才能支持取消AlarmManager)
【android|android AlarmService】
Java代码
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- Intent intent =new Intent(Main.this, alarmreceiver.class);
- intent.setAction("repeating");
- PendingIntent sender=PendingIntent
- .getBroadcast(Main.this, 0, intent, 0);
- AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
- alarm.cancel(sender);
- Intent intent =new Intent(Main.this, alarmreceiver.class);
- intent.setAction("repeating");
- PendingIntent sender=PendingIntent
- .getBroadcast(Main.this, 0, intent, 0);
- AlarmManager alarm=(AlarmManager)getSystemService(ALARM_SERVICE);
- alarm.cancel(sender);