android - Notification intent activity -

i got issue regarding notification intent. have 2 activity (a & b). activity main activity of application. first activity user go through. activity b when user enter clicking on button @ activity a.

the thing when clicked on notification , direct me activity b. direct me activity onbackpressed. when close application , open through multi-tasking option, resume application @ activity b. wanted application start @ activity instead after closing it.

the order should

activity --> activity b.

notification onclick -> activity b (onbackpressed) -> activity --> close.

re-open app / open multi-tasking feature --> activity a

please let me know if there other information can provide proper understanding question.

gcm_intent.class

    notification note = new notification(icon, msgtopic ,system.currenttimemillis());     intent i=new intent(this, activity_b.class);     i.putextra("topicid", topicid);     i.setflags(intent.flag_activity_clear_top|     intent.flag_activity_single_top);     pendingintent pi=pendingintent.getactivity(this, communitiesappconstant.notification_id, i,  pendingintent.flag_cancel_current | pendingintent.flag_one_shot);     note.setlatesteventinfo(this, topicname ,msginfo+message, pi);     note.flags |= notification.flag_auto_cancel | notification.flag_show_lights;     note.ledargb |= 0xff0000ff;     note.ledoffms |= 1000;     note.ledonms |= 300;       mgr.notify(communitiesappconstant.notification_id, note); 

activity b.class

@override public void oncreate(bundle savedinstancestate){      super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_b);     bundle bundle = getintent().getextras();     topicid = bundle.getstring("topicid");  }  @override public void onbackpressed() {     super.onbackpressed();     log.e(tag,  "onbackpressed");     intent = new intent(activity_b.this, activity_a.class);     i.addflags(intent.flag_activity_clear_top);     startactivity(i);     finish(); } 

notification message can display user outside of application's normal ui.this perfect code use of notification.

notificationcompat.builder mbuilder =         new notificationcompat.builder(this)         .setsmallicon(r.drawable.notification_icon)         .setcontenttitle("my notification")         .setcontenttext("hello world!"); // creates explicit intent activity in app intent resultintent = new intent(this, resultactivity.class);  // stack builder object contain artificial stack // started activity. // ensures navigating backward activity leads out of // application home screen. taskstackbuilder stackbuilder = taskstackbuilder.create(this); // adds stack intent (but not intent itself) stackbuilder.addparentstack(resultactivity.class); // adds intent starts activity top of stack stackbuilder.addnextintent(resultintent); pendingintent resultpendingintent =         stackbuilder.getpendingintent(             0,             pendingintent.flag_update_current         ); mbuilder.setcontentintent(resultpendingintent); notificationmanager mnotificationmanager =     (notificationmanager) getsystemservice(context.notification_service); // mid allows update notification later on. mnotificationmanager.notify(mid, mbuilder.build());