android - ListView with Custom ArrayAdapter not updating -

i trying return custom view of textview, chrono, , checkbox. have overriden getview method not sure if did correctly. appreciate comments on arrayadapter. not update in application. thanks!

main java

public class tasktracker extends activity {  /** called when activity first created. */ @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.main);      button addbutton;     addbutton=(button)findviewbyid(r.id.button1);     listview mylistview= (listview)findviewbyid(r.id.listview1);     final edittext myedittext= (edittext)findviewbyid(r.id.edittext1) ;      //final arraylist<string> taskitems = new arraylist<string>();     final ttadapterview aa = new ttadapterview(this);    // aa = new arrayadapter<string>(this, 0);     mylistview.setadapter(aa);       addbutton.setonclicklistener(new onclicklistener(){         public void onclick(view v){             aa.add(myedittext.gettext().tostring());             //taskitems.add(count, myedittext.gettext().tostring());             aa.notifydatasetchanged();             myedittext.settext("");             myedittext.requestfocus();                                         }     });     } 

}

arrayadapter

public class ttadapterview extends arrayadapter<string> {  public view v;  public ttadapterview(context context){     super(context,r.layout.row);  }  @override public view getview(int position, view convertview, viewgroup parent){     this.v = convertview;      if(v==null){         layoutinflater vi = (layoutinflater)getcontext().getsystemservice(context.layout_inflater_service);         v = vi.inflate(r.layout.row, null);     }      return v; } 

you should extend baseadapter rather arrayadapter in listview adapter class. notifydatasetchanged() little bit funky time other extend baseadapter. that's been experience @ least.