public ListAdapter(Context context) {
   this.inflater = LayoutInflater.from(context);
   alphaIndexer = new HashMap<String, Integer>();
   sections = new String[ShowCity_lists.size()];
   for (int i = 0; i < ShowCity_lists.size(); i++) {
     // 当前汉语拼音首字母
     String currentStr = getAlpha(ShowCity_lists.get(i).getPinyi());
     // 上一个汉语拼音首字母,如果不存在为“ ”
     String previewStr = (i - 1) >= 0 ? getAlpha(ShowCity_lists.get(i - 1).getPinyi()) : " ";
     if (!previewStr.equals(currentStr)) {
       String name = getAlpha(ShowCity_lists.get(i).getPinyi());
       alphaIndexer.put(name, i);
       sections[i] = name;
     }
   }
 }
 @Override
 public int getCount() {
   return ShowCity_lists.size();
 }