Thanks for your reply. I'm working like this.
New a Handler in Activity's onCreate(),and after all things init,I send msg to Handler on a non-UI thread.When Handler receive a msg,it update the element or scroll the list by call notifyDataSetChanged and setSelectionFromTop in Handler's handleMessage(Message msg). @Override public void onCreate(Bundle icicle){ super.onCreate(icicle); ....................... ....................... xxxxxxxxx = new Handler() { public void handleMessage(Message msg) { switch(msg.what) { case xxxxxxxx:{ xxx.notifyDataSetChanged(); } break; case xxxxxxxx:{ xxxsetSelectionFromTop (1,20); } break; } } } ................ } In most cases all work well,but sometimes there is the NullPointerException. On 7月15日, 上午10时30分, TreKing <treking...@gmail.com> wrote: > On Wed, Jul 13, 2011 at 4:45 AM, zatenoi <zate...@gmail.com> wrote: > > can anyone help me?thanks very much. > > Debug your code. In particular make sure you're not manipulating anything in > the list on a non-UI thread. > > --------------------------------------------------------------------------- > ---------------------- > TreKing <http://sites.google.com/site/rezmobileapps/treking> - Chicago > transit tracking app for Android-powered devices -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en