头部

private String str[] = {“关注”,“首页”,“我的”};

@Override
protected void initView(View view) {
    tabLayout = view.findViewById(R.id.tabLay);
    viewPager = view.findViewById(R.id.viewp);
    viewPager.setAdapter(new FragmentPagerAdapter(getChildFragmentManager()) {
        @Override
        public Fragment getItem(int i) {
            switch (i){
                case 0:
                    return new Fragment1();
                case 1:
                    return new Fragment02();
                case 2:
                    return new Fragment03();
            }
            return null;
        }
            //str长度
        @Override
        public int getCount() {
            return str.length;
        }
            //获取头部
        @Nullable
        @Override
        public CharSequence getPageTitle(int position) {
            return str[position];
        }


    });
    //关联
    tabLayout.setupWithViewPager(viewPager);
}