java - After scrolling in the listview, elements are swapped -

i writing time-tracking app, every row of listview has 2 buttons(start , stop) , textview display elapsed time.

after scrolling in listview, elements swapped.

i'm not sure in solution, put in model class, viewholder object getting acces changing view elements.

here fragment of code model

private string name; private  boolean isstart=false; private  long elapsedtime=0l,seconds=0l,hours=0l,minutes=0l,lastpause=0l,updatetime=0l,starttime=0l,days=0l; private runnable updatetimethread=new runnable() { @override public void run() {     if(isstart && starttime!=0) {         updatetime = ((system.currenttimemillis() - starttime) + lastpause);         seconds = updatetime / 1000;         minutes = seconds / 60;         hours = minutes / 60;          seconds = seconds % 60;         minutes = minutes % 60;         hours = hours % 24;          holder.days.settext(string.format("%04d", days));         holder.hours.settext(string.format("%02d", hours));         holder.minutes.settext(string.format("%02d", minutes));         holder.seconds.settext(string.format("%02d", seconds));         log.d("mytag",name+" "+seconds);         mainactivity.handler.post(this);     } }              };  myadapter.viewholder holder;      public myadapter.viewholder getholder() { return holder;   }     public void setholder(myadapter.viewholder holder) {     this.holder = holder;    }       public runnable getrunnable() { return updatetimethread;          } 

adapter's fragment code

public view getview(final int position, final view convertview, viewgroup parent) { view row = convertview; final tracker tracker = trackerlist.get(position); final runnable updatetimethread=tracker.getrunnable();   view.onclicklistener onclicklistener; viewholder holder;  if(row == null){     holder = new viewholder();     layoutinflater inflater = ((activity)context).getlayoutinflater();     row = inflater.inflate(r.layout.row,parent,false);     holder.name = (textview)row.findviewbyid(r.id.tvname);     holder.days = (textview)row.findviewbyid(r.id.tvdays);     holder.hours = (textview)row.findviewbyid(r.id.tvhours);     holder.minutes = (textview)row.findviewbyid(r.id.tvminutes);     holder.seconds = (textview)row.findviewbyid(r.id.tvseconds);     holder.start = (button)row.findviewbyid(r.id.btstart);     holder.stop = (button)row.findviewbyid(r.id.btstop);     row.settag(holder); }else {     holder = (viewholder) row.gettag(); }     holder.start.setenabled(true);     holder.stop.setenabled(false);     holder.name.settext(tracker.getname());     final viewholder finalholder = holder;    if(tracker.getisstart()){     holder.start.setenabled(false);     holder.stop.setenabled(true); }    onclicklistener = new view.onclicklistener() {      @override      public void onclick(view v) {          switch (v.getid()) {              case r.id.btstart:                  tracker.setstarttime(system.currenttimemillis());                  tracker.setisstart(true);                  tracker.setholder(finalholder);                  mainactivity.handler.post(updatetimethread);                  finalholder.start.setenabled(false);                  finalholder.stop.setenabled(true);                  break;              case r.id.btstop:                  tracker.setlastpause(tracker.getupdatetime());                  mainactivity.handler.removecallbacks(updatetimethread);                  finalholder.stop.setenabled(false);                  finalholder.start.setenabled(true);                  tracker.setisstart(false);                  break;          }      }  }; holder.start.setonclicklistener(onclicklistener); holder.stop.setonclicklistener(onclicklistener); return row;  }  static class viewholder{ textview  name,days,hours,minutes,seconds; button start,stop; } 

change part

holder.start.setenabled(true); holder.stop.setenabled(false); holder.name.settext(tracker.getname()); final viewholder finalholder = holder;  if(tracker.getisstart()){ holder.start.setenabled(false); holder.stop.setenabled(true); }     

to this

final viewholder finalholfder = holder;  finalholfder.start.setenabled(true); finalholfder.stop.setenabled(false); finalholfder.name.settext(tracker.getname());   if(tracker.getisstart()){ finalholfder.start.setenabled(false); finalholfder.stop.setenabled(true); } else{ finalholfder.start.setenabled(true); finalholfder.stop.setenabled(false); } 

and this

holder.start.setonclicklistener(onclicklistener);   holder.stop.setonclicklistener(onclicklistener); 

to this

 finalholfder.start.setonclicklistener(onclicklistener);  finalholfder.stop.setonclicklistener(onclicklistener);