Android用AlarmManager实现后台任务-android学习之旅(63)

因为Timer不能唤醒cpu,所以会在省电的原因下失效,所以需要唤醒cpu在后台稳定化的执行任务,AlarmManager能够唤醒cpu

这个例子讲解了如何通过Service来在后他每一个小时执行.特定的任务,原理是在Service里面设置一个一小时定时,然后到了一个小时以后启动BroadCast,然后在onReceive方法中再次启动Service,这样每一个小时就启动一次Service,行程循环

代码如下

activity

 protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Intent intent = new Intent(this,LongRunningService.class);        startService(intent);    }

service

public class LongRunningService extends Service {    public LongRunningService() {    }    @Override    public IBinder onBind(Intent intent) {        // TODO: Return the communication channel to the service.        throw new UnsupportedOperationException("Not yet implemented");    }    @Override    public int onStartCommand(Intent intent, int flags, int startId) {        new Thread(new Runnable() {            @Override            public void run() {                Log.d("LongRunningService", "excuted" + new Date().toString());            }        }).start();        AlarmManager manager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);        int anHour = 60*60*1000;        long trigerAtTime = SystemClock.elapsedRealtime()+anHour;        Intent alarmIntent = new Intent(this,AlarmReceive.class);        PendingIntent pendingIntent = PendingIntent.getBroadcast(this,0,alarmIntent,0);        manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP,trigerAtTime,pendingIntent);        return super.onStartCommand(intent, flags, startId);    }}

receiver

public void onReceive(Context context, Intent intent) {        // TODO: This method is called when the BroadcastReceiver is receiving        // an Intent broadcast.        Intent i = new Intent(context,LongRunningService.class);        context.startService(i);    }}

因为Timer不能唤醒cpu,所以会在省电的原因下失效,所以需要唤醒cpu在后台稳定化的执行任务,AlarmManager能够唤醒cpu

这个例子讲解了如何通过Service来在后他每一个小时执行.特定的任务,原理是在Service里面设置一个一小时定时,然后到了一个小时以后启动BroadCast,然后在onReceive方法中再次启动Service,这样每一个小时就启动一次Service,行程循环

代码如下

activity

service

receiver

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