@Override
 public void onStart() {
   super.onStart();
   // 初始化数据
   initData();
   brainAdapter = new BrainAdapter(context, brainItems);
   xListView.setAdapter(brainAdapter);
 }
  @Nullable
  @Override
  public View onCreateView(
      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootview = inflater.inflate(R.layout.fragment_brain_fragment_best, container, false);
    // 获得控件
    xListView = (XListView) rootview.findViewById(R.id.xlistview_brain_best);
    // 必要操作
    xListView.setPullLoadEnable(true);
    context = getActivity();

    return rootview;
  }