android - How to notifydatasetchanged between two activities -

i have 2 activities each contain fragments. activity has fragment listview. rows of listview obtained sqlitedatabase.

activity b contains fragment enables entries of database edited. when user edits database entry, saves data, returns activity via backbutton or:

actionbar = getsupportactionbar(); actionbar.setdisplayhomeasupenabled(true); actionbar.sethomebuttonenabled(true); 

how notify listview in activity there has been change database? understand how communicate between activity , it's fragments, how implement notifydatasetchanged when fragments in 2 different activities?

i suspect going activity via button recalling view stack, view has changed when there database change.

you call notifydatasetchanged in onresume in activity a. when close or go activity b a, update data. don't forget check if adapter different null, otherwise crash first time open app.

you make public function in activity updates list , call activity b.

class activitya  public static void updatelist() {     if(adapter != null){       adapter.notifydatasetchanged;     } }   class activityb  activitya.updatelist(); 

hope helps :)