android - 如何在 FragmentPagerAdapter 中添加 fragment 标签以便稍后引用 fragment ？

Question

我尝试了以下但没有帮助。如何从 FragmentPagerAdapter 设置标签或访问 fragment 标签？

        @Override
public Fragment getItem(int position) {

    MainActivity activity = (MainActivity)mcontext;

    if (position == 0) {
       Fragment discoverFragment =  new DiscoverFragment();
        activity.getSupportFragmentManager().beginTransaction().add(discoverFragment, "discover").commit();
        return discoverFragment;
    } else if (position == 1){
        Fragment myFeedFragment =  new MyFeedFragment();
        activity.getSupportFragmentManager().beginTransaction().add(myFeedFragment, "myfeed").commit();
        return myFeedFragment;
    } else {
        Fragment filterFragment =  new FilterFragment();
        activity.getSupportFragmentManager().beginTransaction().add(filterFragment, "filter").commit();
        return filterFragment;
    }
}

Answer 1

看来您正确设置了标签。无论如何，这种方式应该可行。

设置标签:

MyFeedFragment myFeedFragment= new MyFeedFragment();
getSupportFragmentManager().beginTransaction().add(R.id.fragmentContainer, myFeedFragment, "myfeed");
fragmentTransaction.commit();

然后通过搜索标签就可以得到:

    List fragments = getSupportFragmentManager().getFragments();

    Fragment discoverFrag = null;
    Fragment myFeedFragment = null;
    Fragment filterFragment = null;

    for (int i = 0; i < fragments.size(); i++) {
        if (((Fragment) fragments.get(i)).getTag() == "discover")
            discoverFrag = (Fragment) fragments.get(i);

        if (((Fragment) fragments.get(i)).getTag() == "myfeed")
            myFeedFragment = (Fragment) fragments.get(i);

        if (((Fragment) fragments.get(i)).getTag() == "filter")
            filterFragment = (Fragment) fragments.get(i);
    }