android - How to maintain the position of ListView -

possible duplicate:
maintain/save/restore scroll position when returning listview

how can maintain position of listview in activity when go activity (by launching intent) , come (press button)?

thank you.

declare global variables:

int index = 0; listview list; 

and make reference listview in oncreate():

list = (listview) findviewbyid(r.id.my_list); 

next, in onresume(), add line @ end:

list.setselectionfromtop(index, 0); 

lastly, in onpause, add following line end:

index = list.getfirstvisibleposition();