Dismiss Ongoing Android Notification Via Action Button Without Opening App

Start with this:

int final NOTIFICATION_ID = 1;

//Create an Intent for the BroadcastReceiver
Intent buttonIntent = new Intent(context, ButtonReceiver.class);
buttonIntent.putExtra("notificationId",NOTIFICATION_ID);

//Create the PendingIntent
PendingIntent btPendingIntent = PendingIntent.getBroadcast(context, 0, buttonIntent,0);

//Pass this PendingIntent to addAction method of Intent Builder
NotificationCompat.Builder mb = new NotificationCompat.Builder(getBaseContext());
.....
.....
.....
mb.addAction(R.drawable.ic_Action, "My Action", btPendingIntent);
manager.notify(NOTIFICATION_ID, mb.build());  

Create the BroadcastReceiver:

public class ButtonReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {

        int notificationId = intent.getIntExtra("notificationId", 0);

        // Do what you want were.
        ..............
        ..............

        // if you want cancel notification
        NotificationManager manager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        manager.cancel(notificationId);
    }
}  

If you don´t want show any activity when user click on notification, define the intent passed in setContentIntent in this way:

PendingIntent resultPendingIntent = PendingIntent.getActivity(context,  0, new Intent(), 0);
......
......
mb.setContentIntent(resultPendingIntent); 

To close notification tray when clicked, call setAutoCancel() with true when building the notification: mb.setAutoCancel(true);