android get rssitem description from listview -

in android app i'm using listview populated rssitems taken webpage url; listview shows me title , pubdate of rssitem.

realize when click on rssitem of listview, app shows me alert dialog showing me in message box descritpion of rssitem title.

how can realize it?

here code:

public class mainactivity extends actionbaractivity{      private listview listview;     url url = null;     rssfeed feed = null;     alertdialog.builder alert;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          listview = (listview) findviewbyid(r.id.listview);         alert = new alertdialog.builder(mainactivity.this);          try {             url = new url("http://www.unikore.it/index.php/ingegneria-informatica-home?format=feed");         } catch (malformedurlexception e) {             e.printstacktrace();         }         new readrsstask().execute(url);     }      private class readrsstask extends asynctask<url, void, rssfeed> {          @override         protected rssfeed doinbackground(url... params) {             rssfeed result = null;             url url = params[0];             if (!textutils.isempty(url.tostring())) {                 try {                     result = rssreader.read(url);                 } catch (saxexception e) {                     e.printstacktrace();                 } catch (ioexception e) {                     e.printstacktrace();                 }             }             return result;         }          @override         protected void onpostexecute(rssfeed result) {             if (result != null) {                 arraylist<rssitem> rssitems = (arraylist<rssitem>) result.getrssitems();                 arraylist<string> arraylist = new arraylist<string>();                  (final rssitem rssitem : rssitems) {                     arraylist.add(rssitem.gettitle()+"\n"+rssitem.getpubdate()+"\n");                     arrayadapter<string> lista = new arrayadapter<string>(getbasecontext(),android.r.layout.simple_list_item_1,arraylist);                     listview.setadapter(lista);                     listview.setonitemclicklistener(new adapterview.onitemclicklistener() {                         @override                         public void onitemclick(adapterview<?> parent, view view, int position,long id) {                             alert.settitle(listview.getitematposition(position).tostring());                             alert.setmessage(); //here should set rssitem.getdescription()                             alert.show();                         }                     });                     log.i("rss reader", rssitem.gettitle());                 }             }         }     } } 

you need change here

 alert.show(); 

to

 alertdialog dialog = alert.create(); // missed  dialog.show(): 

edit:

remove loop , move oncreate() after asynctask executed.

  listview.setonitemclicklistener(new adapterview.onitemclicklistener() {                     @override                     public void onitemclick(adapterview<?> parent, view view, int position,long id) {                         alert.settitle(listview.getitematposition(position).tostring());                         alert.setmessage(rssitems.get(position).getdescription()); //here should set rssitem.getdescription()                         alert.show();                     }                 }); 

make arraylist<rssitem> rssitems public static , use

rssitems = (arraylist<rssitem>) result.getrssitems();