Fragment中的RecyclerView初始化

Question

我是使用recycviewview的新手,将它与cardview一起使用,有人可以告诉我如何初始化它吗？

我看到我必须以某种方式将它放在onCreateView中,而不是在ViewCreated中,我的代码:

  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                         @Nullable Bundle savedInstanceState) {

return inflater.inflate(R.layout.fragment_genres, container, false);

以及我在Activity上使用的回收器代码,但现在我想在片段中触发它

  recyclerView = (RecyclerView) getActivity().findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);
    layoutManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(layoutManager);

数据痕迹:

JSON>get>DataModel>Adapter>Recycler>CardView

当我在onCreatedView中使用它时,LogCat说:

  java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.view.View.findViewById(int)' on a null object reference

Answer 1

像这样

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                     @Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_genres, container, false);
recyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(layoutManager);
return v;