由于我将始终有有限数量的通知,并且我可以提前计算已用时间,所以看起来AlarmManager
和BroadcastReceiver
的组合工作得很好。这里是我是如何实现这一点:
我首先创建一个BroadcastReceiver
public class NotificationReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
//Get handle to system notification manager
NotificationManager mNM = (NotificationManager)context.getSystemService(Context.NOTIFICATION_SERVICE);
//Get message from intent
Bundle bundle = intent.getExtras();
CharSequence text = bundle.getString("notification_message");
// Set the icon, scrolling text and timestamp
Notification notification = new Notification(R.drawable.notification_icon, text, System.currentTimeMillis());
// The PendingIntent to launch our activity if the user selects this notification
PendingIntent contentIntent = PendingIntent.getActivity(context, 0, new Intent(context, MainActivity.class), 0);
// Set the info for the views that show in the notification panel.
notification.setLatestEventInfo(context, context.getText(R.string.app_name),text, contentIntent);
// Set Flags
notification.flags |= Notification.FLAG_AUTO_CANCEL;
// Send the notification.
mNM.notify(R.string.notification, notification);
}
}
然后,我创建了一个使用AlarmManager
创建一个类/取消发送消息给BroadcastReceiver
public class NotificationSender {
private AlarmManager mAlarmManager;
private Context mContext;
private Intent mIntent;
public NotificationSender(Context context){
this.mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
this.mIntent = new Intent(context, NotificationReceiver.class);
this.mContext = context;
}
public void setAlarm(Long etaMillis, int accumulator){
//Create intent to send to Receiver
this.mIntent.putExtra("notification_message","Message");
//Use accumulator as requestCode so we can cancel later
PendingIntent sender = PendingIntent.getBroadcast(this.mContext, accumulator, this.mIntent, PendingIntent.FLAG_UPDATE_CURRENT);
//Set Alarm
mAlarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, etaMillis, sender);
}
public void cancelAlarms(){
//requestCode (accumulator) will always be a multiple of 10 and less than 100
for (int x = 10; x <= 100; x += 10){
PendingIntent operation = PendingIntent.getBroadcast(this.mContext, x, this.mIntent, PendingIntent.FLAG_UPDATE_CURRENT);
mAlarmManager.cancel(operation);
}
}
public void createAlarms(PreferenceHelper prefs){
//Calculate time notifications are due and set an alarm for each one
//PreferenceHelper is a class to help pull values from shared preferences
Date currentTime = new Date();
for (int i = prefs.getNotificationInterval(); i <= 100; i += prefs.getNotificationInterval()) {
if (i > prefs.getAccumulator()) {
this.setAlarm(SystemClock.elapsedRealtime() + calculateETA(i, prefs).getTime() - currentTime.getTime(), i);
}
}
}
public void refreshAlarms(PreferenceHelper prefs){
this.cancelAlarms();
if (prefs.isNotificationsEnabled()) this.createAlarms(prefs);
}
}
报警
重要的部分是使用累加器作为requestCode
,因此我们可以稍后取消所有的报警。
最后我在onCreate()
调用refreshAlarms()
并且每当用户修改是相关的调度通知偏好使用的NotificationSender
类在我的活动。重新启动手机将清除所有闹钟,以便在通知开始前必须重新启动应用程序。如果系统碰巧杀死了进程,报警仍然会在适当的时候触发。
即使我杀了应用程序,它仍会运行吗? –