Android SwipeRefreshLayout setOnRefreshLayout空引用片段

我正在使用一个片段来运行webview，我希望在向下滑动时刷新它，但是

当我运行应用程序时，swipeRefreshLayout返回null

 * A simple {@link Fragment} subclass.
 * Use the {@link LiveFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class LiveFragment extends Fragment implements SwipeRefreshLayout.OnRefreshListener {
    WebView webView;
    SwipeRefreshLayout refreshLayout;
    String url = "https://m.facebook.com/pages/category/Non-Governmental-Organization--NGO-/AfrikaMedia247-105319351628446/";
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

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

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment LiveFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static LiveFragment newInstance(String param1, String param2) {
        LiveFragment fragment = new LiveFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @SuppressLint("SetJavaScriptEnabled")
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.fragment_youtube, container, false);
        refreshLayout = (SwipeRefreshLayout) v.findViewById(R.id.refreshLayout);
        webView = (WebView) v.findViewById(R.id.webView);

        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().setAllowContentAccess(true);
        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setDatabaseEnabled(true);
        webView.getSettings().setDomStorageEnabled(true);
        webView.setWebViewClient(new myWebViewclient());
        webView.loadUrl(url);
        refreshLayout.setOnRefreshListener(this);

        return v;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        webView.destroy();
    }

    @Override
    public void onRefresh() {
        webView.reload();
        refreshLayout.setRefreshing(false);
    }


    public class myWebViewclient extends WebViewClient {

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }

        @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            Toast.makeText(getActivity(), "No internet connection", Toast.LENGTH_LONG).show();
            webView.loadUrl("file:///android_asset/lost.html");
        }

        @Override
        public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
            super.onReceivedSslError(view, handler, error);
            handler.cancel();
        }





    }
}

这是我运行它时它给我的错误：

Attempt to invoke virtual method 'void androidx.swiperefreshlayout.widget.SwipeRefreshLayout.setOnRefreshListener(androidx.swiperefreshlayout.widget.SwipeRefreshLayout$OnRefreshListener)' on a null object reference

---

我尝试了来自的方法，但无效。

请在

fragment\u youtube.xml中检查swiperefreshlayout的id

我已检查过，要确保只有这一行导致NPE，请尝试删除该行。如果刷新布局仍然抛出NPE，则id不正确或不存在于fragment_youtube中。我确实删除了该行