@Override
 public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int position, long arg3) {
   // TODO Auto-generated method stub
   initTileBar(true);
   mAdapter.setMultiChoiseMode(true);
   mAdapter.notifyDataSetChanged();
   return true;
 }
 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
   if (keyCode == KeyEvent.KEYCODE_BACK) {
     if (mAdapter != null && mAdapter.getMultiChoiseMode()) {
       mAdapter.setMultiChoiseMode(false);
       initTileBar(false);
       mAdapter.clearSelect();
       mAdapter.notifyDataSetChanged();
       return true;
     }
   }
   return super.onKeyDown(keyCode, event);
 }