簡単にTabLayoutとViewPagerを組み合わせる方法について

完成イメージ

ソースコード

Main1Fragment.javaとMain1Fragment.java、fragment_main1.xmlとfragment_main2.xmlは、それぞれ同じ内容です。

MainActivity.java

import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity
{
private CharSequence[] tabTitle = {"タブ1", "タブ2", "タブ3"};
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentPagerAdapter adapter = new FragmentPagerAdapter(getSupportFragmentManager())
{
@Override
public Fragment getItem(int position)
{
switch (position)
{
case 0:
return new Main1Fragment();
case 1:
return new Main2Fragment();
case 2:
return new Main1Fragment();
                    default:
return null;
}
}
@Override
public CharSequence getPageTitle(int position)
{
return tabTitle[position];
}
@Override
public int getCount()
{
return tabTitle.length;
}
};
ViewPager viewPager = findViewById(R.id.viewPager);
viewPager.setOffscreenPageLimit(tabTitle.length);
viewPager.setAdapter(adapter);
TabLayout tabLayout = findViewById(R.id.tabLayout);
tabLayout.setupWithViewPager(viewPager);
}
}

Main1Fragment.java

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Main1Fragment extends Fragment
{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_main1, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
}
}

Main2Fragment.java

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class Main2Fragment extends Fragment
{
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_main2, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
}
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    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"
    android:orientation="vertical"
    tools:context=".MainActivity">
<android.support.design.widget.TabLayout
        android:id="@+id/tabLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
<android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

fragment_main1.xml

<LinearLayout
    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"
    android:orientation="vertical"
    tools:context=".Main1Fragment">
<TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="fragment1" />
</LinearLayout>

fragment_main2.xml

<LinearLayout
    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"
    android:orientation="vertical"
    tools:context=".Main2Fragment">
<TextView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="fragment2" />
</LinearLayout>

build.gradle

dependencies
{
// 以下を追加
implementation 'com.android.support:design:27.1.1'
}

以上、簡単にTabLayoutとViewPagerを組み合わせる方法についてでした。