更改导航栏菜单时缺少某些 tablayout 片段

Question

因此，我将 BottomNavbar 与 Tablayout 结合使用，一开始它工作正常，但是当我从 home 底部导航栏更改菜单然后再次返回 menu 时，其中一个 tablayout 片段消失了像这样：

正如您在图片中看到的那样，起初它工作得很好，但是当我切换到主页然后再次返回菜单时，选项卡 minuman 的 fragment 消失了

这是我的代码：

Layout

fragment_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".MenuFragment">

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <com.google.android.material.tabs.TabLayout
            android:id="@+id/tabLayoutView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/pal1c3"
            app:tabTextColor="@color/white"
            app:tabIndicatorColor="@color/black"/>
    </com.google.android.material.appbar.AppBarLayout>
    <androidx.viewpager.widget.ViewPager
        android:id="@+id/containerViewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:layout_editor_absoluteX="8dp"
        android:layout_below="@+id/appBarLayout"/>
</RelativeLayout>


</FrameLayout>

fragment_makanan_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ViewMenuHome.MakananMenuFragment">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/black"
        android:layout_gravity="center"
        android:gravity="center"
        android:textSize="30sp"
        android:text="Hello text"/>
    

</FrameLayout>

fragment_jajanan_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ViewMenuHome.JajananMenuFragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textColor="@color/black"
        android:textSize="30sp"
        android:text="Jajanan Menu Fragment" />

</FrameLayout>

fragment_minuman_menu.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".ViewMenuHome.MinumanMenuFragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:textColor="@color/black"
        android:textSize="30sp"
        android:text="@string/hello_blank_fragment" />

</FrameLayout>

Java

MenuFragment.java

package com.example.pesanpalgading20;

import android.content.Context;
import android.os.Bundle;

import androidx.fragment.app.Fragment;
import androidx.viewpager.widget.ViewPager;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.material.tabs.TabLayout;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link MenuFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class MenuFragment extends Fragment {

    TabLayout tabLayout;
    ViewPager viewPager;
    Context context;

    // 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 MenuFragment() {
        // 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 MenuFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static MenuFragment newInstance(String param1, String param2) {
        MenuFragment fragment = new MenuFragment();
        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 viewRoot = inflater.inflate(R.layout.fragment_menu, container, false);
        tabLayout = (TabLayout)viewRoot.findViewById(R.id.tabLayoutView);
        viewPager = (ViewPager)viewRoot.findViewById(R.id.containerViewPager);

        context = container.getContext();

        tabLayout.addTab(tabLayout.newTab().setText("Makanan"));
        tabLayout.addTab(tabLayout.newTab().setText("Minuman"));
        tabLayout.addTab(tabLayout.newTab().setText("Jajanan"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

        final MyAdapter adapter = new MyAdapter(getActivity(),getFragmentManager(),tabLayout.getTabCount());
        viewPager.setAdapter(adapter);

        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());

            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });
        // Inflate the layout for this fragment
        return viewRoot;
    }
}

MyAdapter.java

package com.example.pesanpalgading20;

import android.content.Context;

import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;

import com.example.pesanpalgading20.ViewMenuHome.JajananMenuFragment;
import com.example.pesanpalgading20.ViewMenuHome.MakananMenuFragment;
import com.example.pesanpalgading20.ViewMenuHome.MinumanMenuFragment;

public class MyAdapter extends FragmentPagerAdapter {
    private Context myContext;
    int totalTabs;

    public MyAdapter (Context context, FragmentManager fm, int totalTabs){
        super(fm);
        myContext = context;
        this.totalTabs = totalTabs;
    }

    //fragment per tabs

    @Override
    public Fragment getItem(int position){
        switch(position){
            case 0:
                MakananMenuFragment makananMenuFragment = new MakananMenuFragment();
                return makananMenuFragment;
            case 1:
                MinumanMenuFragment minumanMenuFragment = new MinumanMenuFragment();
                return minumanMenuFragment;
            case 2:
                JajananMenuFragment jajananMenuFragment = new JajananMenuFragment();
                return jajananMenuFragment;
            default: return null;
        }
    }

    //counts total number of tabs
    @Override
    public int getCount() {
        return totalTabs;
    }
}

马卡南MenuFragment.java

package com.example.pesanpalgading20.ViewMenuHome;

import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ExpandableListView;

import com.example.pesanpalgading20.R;
import com.example.pesanpalgading20.ToppingAdapter.ToppingAdapter;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link MakananMenuFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class MakananMenuFragment extends Fragment {

    ExpandableListView expandableListTopping;
    List<String> listGroup;
    HashMap<String,List<String>> listItem;
    ToppingAdapter toppingAdapter;

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

    public MakananMenuFragment(String mParam1) {
        this.mParam1 = mParam1;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View viewRoot = inflater.inflate(R.layout.fragment_makanan_menu, container, false);



        // Inflate the layout for this fragment
        return viewRoot;

    }
}

JajananMenuFragment.java

package com.example.pesanpalgading20.ViewMenuHome;

import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.pesanpalgading20.R;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link JajananMenuFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class JajananMenuFragment extends Fragment {

    // 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";

    public JajananMenuFragment(String mParam1) {
        this.mParam1 = mParam1;
    }

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

    public JajananMenuFragment() {
        // 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 JajananMenuFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static JajananMenuFragment newInstance(String param1, String param2) {
        JajananMenuFragment fragment = new JajananMenuFragment();
        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) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_jajanan_menu, container, false);
    }
}

MinumanMenuFragment

package com.example.pesanpalgading20.ViewMenuHome;

import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.example.pesanpalgading20.R;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link MinumanMenuFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class MinumanMenuFragment extends Fragment {

    public MinumanMenuFragment(String mParam1) {
        this.mParam1 = mParam1;
    }

    // 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 MinumanMenuFragment() {
        // 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 MinumanMenu.
     */
    // TODO: Rename and change types and number of parameters
    public static MinumanMenuFragment newInstance(String param1, String param2) {
        MinumanMenuFragment fragment = new MinumanMenuFragment();
        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) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_minuman_menu, container, false);
    }
}

Answer 1

所以我在

中找到了解决方案

原来问题出在我的 MenuFragment.java

中的 getFragmentmanager()

当我改成getChildFragmentManager()就没问题了

更改导航栏菜单时缺少某些 tablayout 片段

Certain tablayout fragment is missing when changing navigationbar menu

java

android

android-studio

android-fragments

android-tablayout