Android管理器5秒后未发出通知

Question

I am trying to use alarm manager to show notification after 5 sec. I have tried many sites but was not able to understand please give a simple example for explaining how to use alarm manager and connect notification with it.

I am newbie.

this is function i used to set alarm and I am not getting notification after 5 secs not in emulator nor in android mobile.

public void setAlarm(View view)
{

    Intent alertIntent = new Intent(this, AlertReciver.class);

    Long alertTime = new GregorianCalendar().getTimeInMillis()+5*1000;

    AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

    alarmManager.set(AlarmManager.RTC_WAKEUP, alertTime, PendingIntent.getBroadcast(this, 1, alertIntent, PendingIntent.FLAG_UPDATE_CURRENT));

tv.setText("completed");
}

and this class to make it work

public class AlertReciver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
    createNotification(context,"times Up", "5 SEcond has passed", "Alert");

}

public void createNotification(Context context,String msg, String msgText, String msgAlert){

    PendingIntent notificIntent = PendingIntent.getActivity(context, 0, new Intent(context, MainActivity.class), 0);

    NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
            .setSmallIcon(R.drawable.ne)
            .setContentTitle(msg)
            .setTicker(msgAlert)
            .setContentText(msgText);

    mBuilder.setContentIntent(notificIntent);

    mBuilder.setDefaults(NotificationCompat.DEFAULT_SOUND);

    mBuilder.setAutoCancel(true);

    NotificationManager mNotificationManager = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);

    mNotificationManager.notify(1, mBuilder.build());


}

}

Answer 1

See: https://developer.android.com/reference/android/app/AlarmManager.html

Note: Beginning with API 19 (KITKAT) alarm delivery is inexact: the OS will shift alarms in order to minimize wakeups and battery use. There are new APIs to support applications which need strict delivery guarantees; see setWindow(int, long, long, PendingIntent) and setExact(int, long, PendingIntent). Applications whose targetSdkVersion is earlier than API 19 will continue to see the previous behavior in which all alarms are delivered exactly when requested.