android - How to update ListFragment on Runtime -

i developing app in there 3 pan layout fragments , each fragments listfragment. communicating between them via interface not able update listview new items. here code of listview need updated:

public class subchapterslistfragment extends sherlocklistfragment {      public interface onsubchapterselectlistener {         public void onsubchapterselected(int position);     }          @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     madapter = null; }      @override     public void onstart() {         super.onstart();         if (getfragmentmanager().findfragmentbyid(                 r.id.sub_sub_category_fragment) != null) {             getlistview().setchoicemode(listview.choice_mode_single);         }     }          // function invoked fragment (succesffully invoked)     public void updatelist(int position) {         log.d("success", "" + position); // position passed         int layout = build.version.sdk_int >= build.version_codes.honeycomb ? android.r.layout.simple_list_item_activated_1                 : android.r.layout.simple_list_item_1;         arraylist<string> items = new arraylist<string>(); //      chapter instance = competitiveprogramming.chapterlist.get(position);         (int = 0; < competitiveprogramming.chapterlist.get(position).subchapterlist.size(); i++) {             items.add(competitiveprogramming.chapterlist.get(position).subchapterlist.get(i).subchaptertitle);         }                 // okay till                 setlistadapter(new arrayadapter<string>(getsherlockactivity(), layout, items)); // not working in line , crashed     } } 

how update listview in runtime?

update:

public class subchapterslistfragment extends sherlocklistfragment {     onsubchapterselectlistener mcallback;      public interface onsubchapterselectlistener {         public void onsubchapterselected(int prev, int position);     }     arrayadapter<string> madapter;     int mposition;      @override     public void onactivitycreated(bundle savedinstancestate) {         super.onactivitycreated(savedinstancestate);         arraylist<string> items = new arraylist<string>();         int layout = build.version.sdk_int >= build.version_codes.honeycomb ? android.r.layout.simple_list_item_activated_1                 : android.r.layout.simple_list_item_1;         chapter instance = competitiveprogramming.chapterlist.get(0);         (int = 0; < instance.subchapterlist.size(); i++) {             items.add(instance.subchapterlist.get(i).subchaptertitle);         }         madapter = new arrayadapter<string>(getsherlockactivity(), layout, items);         setlistadapter(madapter);     }      @override     public void onstart() {         super.onstart();         if (getfragmentmanager().findfragmentbyid(                 r.id.sub_sub_category_fragment) != null) {             getlistview().setchoicemode(listview.choice_mode_single);         }     }      public void updatelist(int position) {         mposition = position;         madapter.clear();         arraylist<string> items = new arraylist<string>();         (int = 0; < competitiveprogramming.chapterlist.get(position).subchapterlist.size(); i++) {             items.add(competitiveprogramming.chapterlist.get(position).subchapterlist.get(i).subchaptertitle);         }         madapter.notifydatasetchanged();     }      @override     public void onlistitemclick(listview l, view v, int position, long id) {         mcallback.onsubchapterselected(mposition, position);         getlistview().setitemchecked(position, true);     }  } 

try this:

madapter.clear(); (int = 0; < competitiveprogramming.chapterlist.get(position).subchapterlist.size(); i++) {         madapter.add(competitiveprogramming.chapterlist.get(position).subchapterlist.get(i).subchaptertitle); } madapter.notifydatasetchanged();