FragmentStatePagerAdapter写法

为了节省资源，分批加载数据
//适配器
class TabLayoutViewPagerAdapter extends FragmentStatePagerAdapter {

    public TabLayoutViewPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public int getItemPosition(Object object) {
        return POSITION_NONE;
    }

    @Override
    public Fragment getItem(int position) {
        return fragmentList.get(position);
    }

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

    @Override
    public CharSequence getPageTitle(int position) {
        return titles.get(position);
    }
}