@Override
 public View getView(int position, View convertView, ViewGroup parent) {
   if (convertView == null) {
     convertView = getLayoutInflater().inflate(R.layout.tab_top, parent, false);
   }
   TextView textView = (TextView) convertView;
   // 用了固定宽度可以避免TextView文字大小变化,tab宽度变化导致tab抖动现象
   textView.setWidth(DisplayUtil.dipToPix(getApplicationContext(), 50));
   textView.setText(String.valueOf(position));
   return convertView;
 }