/**
  * 保存数据
  *
  * @param v 视图
  */
 public void saveData(View v) {
   String userString = mUserET.getText().toString().trim();
   User mUser = new User();
   if (userString.equals("")) {
     return;
   }
   mUser.setName(userString);
   mUser.setRole(currentRole);
   for (int i = 0; i < mUsers.size(); i++) {
     if (userString.equals(mUsers.get(i).getName())) {
       mUsers.remove(i);
     }
   }
   mUsers.add(mUser);
   getUser();
   mAdapter.notifyDataSetChanged();
 }