android - checking if mainActivity is called from another activity -

android - checking if mainActivity is called from another activity -

in application go mainactivity trackingactivity , later mainactivity. in lastly step utilize putextra's. code going mainactivity:

public void gotohomewithdata(){ intent intent = new intent(this, mainactivity.class); intent.putextra("avgspeed", avgspeed); intent.putextra("totaldistance", totaldistance); intent.putextra("altitude", altitude); intent.putextra("totaltime", totaltime); intent.addflags(intent.flag_activity_single_top); startactivity(intent); }

in onresume() method in mainactivity i'd retreive info like:

string totaltime = getintent().getextras().getstring("totaltime"); double totaldistance = getintent().getextras().getdouble("totaldistance"); double avgspeed = getintent().getextras().getdouble("avgspeed"); double height = getintent().getextras().getdouble("altitude");

but because onresume() called when starting application, app crashes on getintent().getextras().getstring("totaltime"); part since there no intent called mainactivity.

what i'm looking check around getintents see if mainactivity called trackingactivity or not.

thank in advance.

you should startactivityforresult;

in activity 1

protected void launchsecondactivity() { // todo auto-generated method stub intent = new intent(this,secondactivity.class); startactivityforresult(i, 0); }

in sec activity instead of launching new instance of first activity utilize setresult

public void gotohomewithdata(){ intent intent = new intent(); intent.putextra("avgspeed", avgspeed); intent.putextra("totaldistance", totaldistance); intent.putextra("altitude", altitude); intent.putextra("totaltime", totaltime); intent.addflags(intent.flag_activity_single_top); setresult(result_ok,intent); finish(); }

then in first activity can hear result so:

@override protected void onactivityresult(int requestcode, int resultcode, intent data) { super.onactivityresult(requestcode, resultcode, data); if (resultcode == result_ok && data!=null) { if (data.getextras().containskey("sometag") { theextrayoucareabout = data.getstringextra("sometag"); } }

note pseudo code should set on right path

android android-intent android-activity bundle