带有android片段的setUserVisibleHint

Question

现在，我想使用Parse添加服务器拉请求，将列表中的数据添加到适配器，并在用户查看页面后填充recyclerview，这样

1）我是否应该添加setUserVisisbleHint中的所有代码，并只添加0.5秒延迟，以便在调用setContentView后执行它，以确保不出现空指针异常错误或

2）是否有更好的方法/其他功能可以实现相同的功能？

public class NewsFeed extends Fragment {
        LinearLayoutManager mLayoutManager;
        boolean _areLecturesLoaded=false;
        View v;
        ProgressBar bar;

        public NewsFeed() {
            // Required empty public constructor
        }

        @Override
        public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                                 @Nullable Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            v=inflater.inflate(R.layout.fragment_news_feed, container, false);

            RecyclerView mRecyclerView = (RecyclerView)v.findViewById(R.id.recycler_view);
            mRecyclerView.setHasFixedSize(true);
            mLayoutManager = new LinearLayoutManager(v.getContext());
            mRecyclerView.setLayoutManager(mLayoutManager);    
            MyStickyAdapter mAdapter = new MyStickyAdapter(v.getContext());    
            mRecyclerView.setAdapter(mAdapter);
           // mRecyclerView.addItemDecoration(new StickyRecyclerHeadersDecoration(mAdapter));
            return v;
        }

        @Override
        public void setUserVisibleHint(boolean isVisibleToUser) {
            super.setUserVisibleHint(isVisibleToUser);
            if (isVisibleToUser && !_areLecturesLoaded ) {
                _areLecturesLoaded = true;
                v.findViewById(R.id.asd).setVisibility(View.GONE);
            }
        }


    }//Closes Fragment

Answer 1

我强烈建议避免增加延迟，特别是在主线程上运行时。若要避免NPE，请尝试在膨胀视图后将findViewById（r.id.asd）移动到onCreateView方法中：

@Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        v=inflater.inflate(R.layout.fragment_news_feed, container, false);
        v.findViewById(R.id.asd).setVisibility(View.GONE);

这是假设r.id.asd位于r.layout.fragment_news_feed中

这篇文章还可以提供一些见解：在片段中的onCreateView之前调用setUserVisibleHint