Android-AlarmManager(全局定时器/闹钟)
android 检测碰撞 汇总
http://www.eoeandroid.com/thread-203518-1-1.html
http://www.eoeandroid.com/thread-203518-1-1.html
Android 3D特效源码汇总
http://www.eoeandroid.com/thread-203549-1-1.html
http://www.eoeandroid.com/thread-203549-1-1.html
仿Siri的中文语音助理源码
http://www.eoeandroid.com/thread-203444-1-1.html
http://www.eoeandroid.com/thread-203444-1-1.html
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
//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();
注意:receiver记得在manifest.xml注册
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(); } } }
(2)周期性的执行某项操作
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);
AlarmManager的setRepeating()相当于Timer的Schedule(task,delay,peroid);有点差异的地方时Timer这个方法是指定延迟多长时间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)
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);