android - Edit sharedPreferences with two different activities to affect change in third activity -

i know sharedpreferences, confused this. know put things sharedpreferences, this:

let's activity a:

sharedpreferences preferences=getsharedpreferences("numbers",mode_private); sharedpreferences.editor edit=preferences.edit(); string a=ed.gettext().tostring(); string b=ed1.gettext().tostring(); editor.putstring("num1",a); editor.putstring("num2",b); editor.apply(); 

and out in activity b,

sharedpreferences preferences=getsharedpreferences("numbers",mode_private); string numberone=preferences.getstring("num1",""); string numbertwo=preferences.getstring("num2",""); 

and set textview in activity b :

textview both; both.settext(numberone + " " + numbertwo); 

but if want edit in sharedpreferences in activity c?? looking online on how , article here

http://codetheory.in/android-application-data-storage-sharedpreferences/

it said had call again different string value so

activity c:

sharedpreferences preferences=getsharedpreferences("numbers",mode_private); sharedpreferences.editor edit=preferences.edit(); string c=ed3.gettext().tostring(); string d=ed4.gettext().tostring(); editor.putstring("num1",c); editor.putstring("num2",d); editor.apply(); 

and when done, should update add in activity b 29 , not 12 more. problem is, not edit sharedpreferences. there way this? why won't update addition in activity b?

you loading values in oncreate()

that method gets called 1 activity lifetime. when rotate phone activity gets destroyed , rebuilt, calling oncreate() again.

a possible solution load values in onresume() way have them come other activity.