将上个问题所涉及的页面和代码全部显示出来

由于上一个问题涉及到的内容较多，我会尽量提供一个简化版的示例，展示如何使用`FragmentPagerAdapter`和`Viewpager`配合一个按钮来进行`Fragment`切换。假设你有一个MainActivity、一个BaseFragment作为基础类，以及FirstFragment和SecondFragment作为具体的`Fragment`实例：

**MainActivity.java**

import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    private static final String[] FRAGMENTS = {"FirstFragment", "SecondFragment"};
    private int currentFragmentIndex = 0;
    private ViewPager viewPager;
    private Button switchButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        viewPager = findViewById(R.id.view_pager);
        switchButton = findViewById(R.id.switch_button);

        setupViewPager(viewPager);
        setupSwitchButton();

        viewPager.setAdapter(adapter);
    }

    private void setupViewPager(ViewPager viewPager) {
        FragmentAdapter adapter = new FragmentAdapter(getSupportFragmentManager());
        for (String tag : FRAGMENTS) {
            adapter.addFragment(tag);
        }
        viewPager.setAdapter(adapter);
    }

    private void setupSwitchButton() {
        switchButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                currentFragmentIndex = (currentFragmentIndex + 1) % FRAGMENTS.length;
                viewPager.setCurrentItem(currentFragmentIndex, true); // 切换到新Fragment
            }
        });
    }

    private class FragmentAdapter extends FragmentStatePagerAdapter {
        private List<String> fragments = new ArrayList<>();

        public FragmentAdapter(FragmentManager fragmentManager) {
            super(fragmentManager);
        }

        public void addFragment(String tag) {
            fragments.add(tag);
        }

        @Override
        public Fragment getItem(int position) {
            return BaseFragment.createInstance(FRAGMENTS[position]);
        }

        @Override
        public int getCount() {
            return fragments.size();
        }
    }
}

**activity_main.xml**

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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=".MainActivity">

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:tabGravity="fill"
        app:tabMode="scrollable"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/switch_button"
        app:layout_constraintTop_toBottomOf="@id/tab_layout"/>

    <Button
        android:id="@+id/switch_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="切换Fragment"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintStart_toStartOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>

在这个例子中，我们没有显示具体的Fragment代码，因为它们通常是继承自BaseFragment并包含各自的视图和业务逻辑。对于`Fragment`间的通信，可以使用`setArguments()`和`getArguments()`来传递数据。