无法显示联系人

Question

我是编程新手，我正在创建一个可以显示联系人的项目，但我在下一行收到错误，

  

rvContacts =（RecyclerView）rootview.findViewById（R.id.contact）;

public class ContactsFragment extends Fragment {
    private ContactsAdapter contactsAdapter;
    private ArrayList<Contacts> contactList = new ArrayList<Contacts>();
    private RecyclerView rvContacts;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootview= inflater.inflate(R.layout.contacts,container,false);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity()) {
            @Override
            protected int getExtraLayoutSpace(RecyclerView.State state) {
                return 300;
            }
        };
        rvContacts = (RecyclerView) rootview.findViewById(R.id.contact);
        //rvContacts.setLayoutManager(LinearLayoutManager);
        rvContacts.addOnItemTouchListener(
                new RecyclerItemClickListener (getActivity(), new RecyclerItemClickListener.OnItemClickListener() {
                    public void onItemClick(View view, int position) {
                        // TODO Handle item click
                        Intent call = new Intent(Intent.ACTION_CALL, Uri.parse("tel:"
                                + contactList.get(position).getContact()));
                        startActivity(call);
                    }
                })
        );
        rvContacts.setOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    //                FeedContextMenuManager.getInstance().onScrolled(recyclerView, dx, dy);
            }
        });
        new AsyncHttpTask().execute();
        return rootview;
    }
    public class AsyncHttpTask extends AsyncTask<String, Void, Integer> {
        @Override
        protected void onPreExecute() {
    //            setProgressBarIndeterminateVisibility(true);
        }
        @Override
        protected Integer doInBackground(String... params) {
            Integer result = 0;
            if (addStaticData().size() != 0) {
    //                contactsAdapter = new ContactsAdapter(getActivity(), contactList);
                result = 1;
            } else {
                result = 0; //"Failed to fetch data!";
            }
            return result; //"Failed to fetch data!";
        }
        @Override
        protected void onPostExecute(Integer result) {
            // Download complete. Let us update UI
            System.out.println("check 3");
            if (result == 1) {
                //contactsAdapter = new ContactsAdapter(getActivity(),contactList);
                rvContacts.setAdapter(contactsAdapter);
            } else {
                Toast.makeText(getActivity(), "Failed to read data!", Toast.LENGTH_SHORT).show();
            }
        }
    }
    private ArrayList<Contacts> addStaticData() {
        contactList.add(new Contacts(R.drawable.ic_person_black_36dp, "Human Resource", "+254755397332"));
        contactList.add(new Contacts(R.drawable.ic_person_black_36dp, "Finance", "+254727438270"));
        contactList.add(new Contacts(R.drawable.ic_person_black_36dp, "OA Sales", "+254727438270"));
        contactList.add(new Contacts(R.drawable.ic_person_black_36dp, "Innovation", "+254755397356"));
        contactList.add(new Contacts(R.drawable.ic_person_black_36dp, "Internal IT", "+254755397230"));
        contactList.add(new Contacts(R.drawable.ic_person_black_36dp, "Help Desk", "+254755397231"));
        return contactList;
    }
    private class ContactsAdapter extends RecyclerView.Adapter {
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            return null;
        }
        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        }
        @Override
        public int getItemCount() {
            return 0;
        }
    }
}