android - ListView won't refresh using notifyDataSetChanged -

i'm trying refresh listview adapter class ( non activity class) tried notifydatasetchanged() wont work , tried call displaylistview() in adapter class crashes well

this displaylistview() method in activityclass

            cursor cursor = dbhelper.fetchallcountries();              // desired columns bound             string[] columns = new string[]{                    dbadapter.qty,                    dbadapter.price,                    dbadapter.product_name             };              // xml defined views data bound             int[] = new int[]{                     r.id.qtyl,                     r.id.pricel,                     r.id.product_namel             };              // create adapter using cursor pointing desired data             //as layout information             dataadapter = new simplecursoradapter(                     this, r.layout.country_inf,                     cursor,                     columns,                     to,                     0);              horizontallistview listview = (horizontallistview) findviewbyid(r.id.cartceckoutlist);             // assign adapter listview                     listview.setadapter(dataadapter);                     dataadapter.notifydatasetchanged(); 

and adapter class use

        package com.abdullahadhaim.finegrillresturant.adater;    public class customlistadapter extends baseadapter { context c; // dbhelper mydatabasehelper ; private activity activity; private layoutinflater inflater; private list<movie> movieitems; imageloader imageloader = appcontroller.getinstance().getimageloader();  dbadapter myadapterdb;  waiteractivity waiteract;  public customlistadapter(activity activity, list<movie> movieitems) {     this.activity = activity;     this.movieitems = movieitems; }  @override public int getcount() {     return movieitems.size(); }  @override public object getitem(int location) {     return movieitems.get(location); }  @override public long getitemid(int position) {     return position; }  @override public view getview(int position, view convertview, viewgroup parent) {      if (inflater == null)         inflater = (layoutinflater) activity                 .getsystemservice(context.layout_inflater_service);     if (convertview == null)         convertview = inflater.inflate(r.layout.list_row, null);      if (imageloader == null)         imageloader = appcontroller.getinstance().getimageloader();     networkimageview thumbnail = (networkimageview) convertview             .findviewbyid(r.id.thumbnail);      final textview title = (textview) convertview.findviewbyid(r.id.title);     textview price = (textview) convertview.findviewbyid(r.id.rating);     // mydatabasehelper=new dbhelper(activity, "cdb", null, 1);     myadapterdb = new dbadapter(activity);     myadapterdb.open();     waiteract = new waiteractivity();      // getting movie data row     final movie m = movieitems.get(position);      // thumbnail image     thumbnail.setimageurl(m.getthumbnailurl(), imageloader);      // title     title.settext(m.gettitle());      // price     price.settext("price: " + "sr " + string.valueof(m.getprice()));      button add = (button) convertview.findviewbyid(r.id.button1);     button plus = (button) convertview.findviewbyid(r.id.plus_butt);     button minus = (button) convertview.findviewbyid(r.id.minus_butt);     final edittext qty = (edittext) convertview             .findviewbyid(r.id.edittext1);      plus.setonclicklistener(new onclicklistener() {          @override         public void onclick(view v) {             // todo auto-generated method stub             string the_qty = qty.gettext().tostring();             int my_qty = integer.parseint(the_qty) + 1;             qty.settext(my_qty + "");          }     });      minus.setonclicklistener(new onclicklistener() {          @override         public void onclick(view v) {             // todo auto-generated method stub             string the_qty = qty.gettext().tostring();             int my_qty = integer.parseint(the_qty) - 1;             qty.settext(my_qty + "");          }     });      add.setonclicklistener(new onclicklistener() {          @override         public void onclick(view v) {             int myqty = integer.parseint(qty.gettext().tostring());             string mytitle = m.gettitle().tostring();             string mycategory = m.getcategory().tostring();             int mycategoryn = m.getordernum();             double myprice = m.getprice() * myqty;              if (myqty == 0)                 toast.maketext(activity, "orders must 1 atleast",                         toast.length_short).show();              else {                  myadapterdb.checkifexcist(activity, "productname", mytitle,                         myqty, myprice, m.getprice(), mytitle, mycategory,                         mycategoryn + "", myqty);                 myadapterdb.deletezeroorlessvalues();               }          }     });      return convertview; }  public void notifydatasetchanged() {     // todo auto-generated method stub     super.notifydatasetchanged(); }   } 

take @ loaders. think prefered way load data datebase views. loaders callbacks if data has changed , view updated you.

http://developer.android.com/guide/components/loaders.html

here tutorial think: http://code.tutsplus.com/tutorials/android-fundamentals-properly-loading-data--mobile-5673