tablayout连接viewpager

public class MainActivity extends AppCompatActivity {

@BindView(R.id.view_pager)
ViewPager viewPager;
@BindView(R.id.tab_layout)
TabLayout tabLayout;
List<Fragment> list = new ArrayList<>();
String[] str = {"首页","新闻","我的"};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.bind(this);

    list.add(new Fragment1());
    list.add(new Fragment2());
    list.add(new Fragment3());
    viewPager.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager()) {
        @Override
        public Fragment getItem(int i) {
            return list.get(i);
        }

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

        @Nullable
        @Override
        public CharSequence getPageTitle(int position) {
            return str[position];
        }
    });

    tabLayout.setupWithViewPager(viewPager);