Android有关tablayout向上滑动停留页面顶部（有待完善）

activity_main布局:

注：在使用AppBarLayout控件时需要导design包

implementation'com.android.support:design:27.+'

MainActivity中：

public class MainActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private CollapsingToolbarLayout toolbar_layout;
    private TabLayout tabLayout;
    private AppBarLayout app_bar;
    private NestedScrollView nestedScrollView;
    private ViewPager viewPager;

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

    }

    private void initView() {
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        //设置返回主页的按钮
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        toolbar_layout = (CollapsingToolbarLayout) findViewById(R.id.toolbar_layout);
        tabLayout = (TabLayout) findViewById(R.id.tabLayout);
        app_bar = (AppBarLayout) findViewById(R.id.app_bar);
        nestedScrollView = (NestedScrollView) findViewById(R.id.nestedScrollView);
        viewPager = findViewById(R.id.viewPager);
        nestedScrollView.setFillViewport(true);

        ResumeAdapter rusumeAdapter = new ResumeAdapter(getSupportFragmentManager());
        viewPager.setAdapter(rusumeAdapter);
        tabLayout.setupWithViewPager(viewPager);
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                nestedScrollView.scrollTo(0,0);
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }
}

适配器：

public class ResumeAdapter extends FragmentPagerAdapter{
    public ResumeAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        Fragment fragment = null;
        if (0 == position) {
            fragment = new AFragment();
        } else if (1 == position) {
            fragment = new BFragment();
        } else if (2 == position) {
            fragment = new CFragment();
        } else if (3 == position) {
            fragment = new DFragment();
        }
        return fragment;
    }

    @Override
    public int getCount() {
        return 4;
    }

    @Nullable
    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
            case 0:
                return "头条";
            case 1:
                return "热点";
            case 2:
                return "娱乐";
            case 3:
                return "体育";
        }
        return null;
    }
}