아주 간단 한 TabLayout+viewpager+fragment(정말 간단 합 니 다)

implementation 'com.android.support:design:28.0.0'

package com.example.lenovo.myapplication.activity;

import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import com.example.lenovo.myapplication.R;
import com.example.lenovo.myapplication.adapter.MyViewPageAdapter;
import com.example.lenovo.myapplication.fragment.RedianFragment;
import com.example.lenovo.myapplication.fragment.TuijianFragment;
import com.example.lenovo.myapplication.fragment.TupianWenFragment;
import com.example.lenovo.myapplication.fragment.XinWenFragment;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
    private List mTitleList;//      
    private List fragments;
    private TabLayout tab_layout;
    private ViewPager view_pager;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        init();
        initData();
    }
    private void init() {
        tab_layout = findViewById(R.id.tab_layout);
        view_pager = findViewById(R.id.view_pager);
    }
    private void initData() {
        mTitleList = new ArrayList<>();
        fragments = new ArrayList<>();
        mTitleList.clear();
        fragments.clear();
        mTitleList.add("  ");
        mTitleList.add("  ");
        mTitleList.add("  ");
        mTitleList.add("  ");
        fragments.add(new XinWenFragment());
        fragments.add(new RedianFragment());
        fragments.add(new TuijianFragment());
        fragments.add(new TupianWenFragment());
        MyViewPageAdapter pageAdapter = new MyViewPageAdapter(getSupportFragmentManager(),mTitleList,fragments);
        view_pager.setAdapter(pageAdapter);
        tab_layout.setupWithViewPager(view_pager);
        tab_layout.setTabsFromPagerAdapter(pageAdapter);
    }
}

package com.example.lenovo.myapplication.adapter;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import java.util.List;
public class MyViewPageAdapter extends FragmentPagerAdapter {
    private final List titleLists;
    private final List fragments;
    public MyViewPageAdapter(FragmentManager fm, List mTitleList, List fragments) {
        super(fm);
        this.titleLists = mTitleList;
        this.fragments = fragments;
    }
    @Override
    public Fragment getItem(int i) {
        return fragments.get(i);
    }
    @Override
    public int getCount() {
        return fragments.size();
    }
    @Override
    public CharSequence getPageTitle(int position) {
        return titleLists.get(position);
    }
}

    
    20sp