android - OnActivityResult is never called -

i have 2 standalone applications. application , application b. want start activity in application b application , results back. in application b there 1 more activity. b second acitivty result b's first activity. want these result application a. onactivityresult in never called. following code.

application a:

public void onclickbtntoapplicationb(view v) {         try {             final intent intent = new intent(intent.action_main, null);             final componentname cn = new componentname("pakacagename","package.class");             intent.setcomponent(cn);             intent.setaction(intent.action_main);             intent.addcategory(intent.category_launcher);         intent.setflags(intent.flag_activity_new_task);                              startactivityforresult(intent, request_code);         } catch (activitynotfoundexception e) {         //handle exception         }      }      public void onactivityresult(int requestcode, int resultcode, intent intent) {         switch (requestcode) {             case request_code:                handleresult(resultcode, intent);                break;         }     }      public void handleresult(int resultcode, intent intentresult) {         switch (resultcode) {             case result_ok:                 string result = intentresult.getstringextra("result");                 // need results application b here..                 break;               case result_canceled:                 break;         }       } 

application b activity 1.class:

intent s = new intent(1.this,2.class); startactivityforresult(s, request_code_b); protected void onactivityresult(int requestcode, int resultcode, intent intentresult) {          switch(requestcode){         case request_code_b:             handleresult(resultcode, intentresult);     } }  public void handleresult(int resultcode, intent intentresult) {     switch (resultcode) {     case result_ok:         string scanresult = intentresult.getstringextra("result");         intent newintent = new intent();         newintent.putextra("result", scanresult);         setresult(activity.result_ok, newintent);         finish();         break;      case result_canceled:         break; } 

from documentation:

note method should used intent protocols defined return result. in other protocols (such action_main or action_view), may not result when expect. example, if activity launching uses singletask launch mode, not run in task , receive cancel result.