从API 27中不推荐使用FragmentStatePagerAdapter

Question

private class MainPagerAdapter extends FragmentStatePagerAdapter {

    MainPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        Fragment result = new DummyFragment();
        return result;
    }

    @Override
    public int getCount() {
        return 5;
    }

}

上面的代码显示fragmentstatePageradapter、getitem(...)和super(...)为不推荐使用。

Answer 1

切换到ViewPager2并改用FragmentStateAdapter。

从那里，您可以使用onPause和onResume回调来确定用户当前可见的片段。当一个片段变得可见时调用onResume，当它停止可见时调用onPause。->阅读更多

基于Eric和Reejesh的评论。

super(@NonNull FragmentManager fm)
super(@NonNull FragmentManager fm, BEHAVIOR_SET_USER_VISIBLE_HINT)

 /**
 * Indicates that Fragment#setUserVisibleHint(boolean) will be 
 * called when the current fragment changes.
 */
@Deprecated
public static final int BEHAVIOR_SET_USER_VISIBLE_HINT = 0;

/**
 * Indicates that only the current fragment will be 
 * in the Lifecycle.State#RESUMED state. All other Fragments 
 * are capped at Lifecycle.State#STARTED.
 */
public static final int BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT = 1;