片段中的WebView不会加载URL

Question

我已经在网站上阅读了有关此问题的所有内容，但没有任何解决方案适合我。 我什至不是初学者，并尝试创建一个4-tab活动。 第一个标签页具有webView，但不会加载网址。 什么东西少了？

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CALL_PHONE" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/Theme.AppCompat.NoActionBar">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <!-- [START firebase_service] -->
    <service android:name=".MyFirebaseMessagingService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT" />
        </intent-filter>
    </service>
    <!-- [END firebase_service] -->
    <!-- [START firebase_iid_service] -->
    <service android:name=".MyFirebaseInstanceIDService">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
        </intent-filter>
    </service>
    <!-- [END firebase_iid_service] -->
    <activity
        android:name=".AnaSayfa"
        android:label="@string/title_activity_ana_sayfa"
        android:theme="@style/Theme.AppCompat.NoActionBar"></activity>
</application>

fragment_frag_home.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="layout.fragHome">

<!-- TODO: Update blank fragment layout -->

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/pembis"
    android:orientation="vertical">

    <WebView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerVertical="true"
        android:id="@+id/webView"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

fragHome.java

package layout;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView;
import android.webkit.WebViewClient;


import com.sahin.spm.R;

/**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link fragHome.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link fragHome#newInstance} factory method to
 * create an instance of this fragment.
 */
public class fragHome extends Fragment {
    private WebView myWebView;
    private String Url = "http://google.com.tr";
    // 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;
    private OnFragmentInteractionListener mListener;

    public fragHome() {
        // 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 fragHome.
     */
    // TODO: Rename and change types and number of parameters
    public static fragHome newInstance(String param1, String param2) {
        fragHome fragment = new fragHome();
        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);
        }

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_frag_home, container, false);
        WebView webView = (WebView) rootView.findViewById(R.id.webView);
        webView.setWebViewClient(new WebViewClient());
        webView.getSettings().setJavaScriptEnabled(true);
        webView.loadUrl("http://www.google.com.tr");
        return rootView;
    }


    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }
}

谢谢你的帮助。

编辑：我认为问题在于以下几行：

View rootView = inflater.inflate(R.layout.fragment_anasayfa, container, false);
WebView myWebView = (WebView) rootView.findViewById(R.id.hWebView);

我认为将定义的对象与现有的webview相关联存在问题。

Answer 1

尝试像这样覆盖setUserVisibleHint ：

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    if (isVisibleToUser){
       webView.loadUrl("http://www.google.com.tr");
    }