android - AsyncTask starts again on tab change with SherlockFragments -

i have mainactivity extends sherlockfragmentactivity , 2 tabs sherlockfragment. these 2 tabs have listview populated asynctask. works fine whenever switch tab tab, asynctask triggers again , want start once.

here mainactivity:

public class mainactivity extends sherlockfragmentactivity {      private fragmenttabhost mtabhost;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          mtabhost = (fragmenttabhost) findviewbyid(android.r.id.tabhost);         mtabhost.setup(this, getsupportfragmentmanager(), r.id.tabcontent);         mtabhost.addtab(mtabhost.newtabspec("tab1").setindicator("tab1"),tab1.class, null);         mtabhost.addtab(mtabhost.newtabspec("tab2").setindicator("tab2"),tab2.class, null);  } 

and here tab1:

public class tab1 extends sherlockfragment {       @override     public view oncreateview(layoutinflater inflater, viewgroup container,         bundle savedinstancestate) {         view v = inflater.inflate(r.layout.tab1, container, false);         return v;      }      @override     public void onstart() {         super.onstart();         // todo auto-generated method stub              new fetchdata().execute();      }      public class fetchdata extends asynctask<string, string, string> {     .....     }  } 

tab2 contains similar code, different mysql select. works fine, data populated on listview each time switch tab1 tab2, asynctask triggers again :/ please ...

the onstart method called each time fragment become visible, e.g. when switch tabs

source: android fragment life cycle

i suggest move:

new fetchdata().execute(); 

into oncreateview method.