Viewpager

  @BindView(R.id.viewPager_item2)
    ViewPager viewPager;
    @BindView(R.id.button1_item2)
    Button button1;
    @BindView(R.id.button2_item2)
    Button button2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        initView();

    }

    private void initView() {
        initToolBar(findViewById(R.id.toolbar), true, getString(R.string.item2));
        //button list
        List buttons = new ArrayList<>();
        buttons.add(button1);
        buttons.add(button2);
        //list fragment
        List fragments = new ArrayList<>();
        fragments.add(new VideoFragment());
        fragments.add(new PictureFragment());
        //创建adapter
        PagerAdapter pagerAdapter = new FragmentPagerAdapter(getSupportFragmentManager()) {
            @Override
            public Fragment getItem(int position) {
                return fragments.get(position);
            }

            @Override
            public int getCount() {
                return fragments.size();
            }
        };
        viewPager.setAdapter(pagerAdapter);
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                for (Button button : buttons) {
                    button.setBackgroundColor(Color.WHITE);
                    button.setTextColor(Color.GRAY);
                }
                switch (position) {
                    case 0:
                        button1.setTextColor(Color.WHITE);
                        button1.setBackgroundColor(Color.GRAY);
                        break;
                    case 1:
                        button2.setTextColor(Color.WHITE);
                        button2.setBackgroundColor(Color.GRAY);
                        break;
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
        button1.setBackgroundColor(Color.GRAY);
        button1.setTextColor(Color.WHITE);
        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                viewPager.setCurrentItem(0);

                for (Button button : buttons) {
                    button.setBackgroundColor(Color.WHITE);
                    button.setTextColor(Color.GRAY);
                }

                button1.setBackgroundColor(Color.GRAY);
                button1.setTextColor(Color.WHITE);
            }
        });
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                viewPager.setCurrentItem(1);
                for (Button button : buttons) {
                    button.setBackgroundColor(Color.WHITE);
                    button.setTextColor(Color.GRAY);
                }
                button2.setBackgroundColor(Color.GRAY);
                button2.setTextColor(Color.WHITE);
            }
        });
    }

    @Override
    protected int getLayout() {
        return R.layout.activity_item2;
    }

    @Override
    public void onPointerCaptureChanged(boolean hasCapture) {

    }