Android getting fragment that is in FragmentPagerAdapter

Question

I have following problem: I have one activity in which I have two tabs which are made both as fragments using FragmentPagerAdapter In some moment I would l

Answer 1

A simpler approach to this is to get the Tags directly from the Fragment Manager; like this:

fm.getFragments().get(0).getTag()

You can replace the position, depending on the fragment you need the tag for. Hope this helps others!.

Answer 2

It is very late to answer this question but i have searched a lot no one tell me the exact answer, Might be some one found it useful.

I have set my fragments through FragmentPagerAdapter and i did communication between fragments

https://developer.android.com/training/basics/fragments/communicating.html#Deliver

following this link and for FindFragmentById i simply used viewpager.getId() on the mainactivity .

Answer 3

The Fragments supplied by the FragmentPagerAdapter are auto-tagged when they're instantiated. You can retrieve the tag with this method:

private static String makeFragmentName(int viewPagerId, int index) {
     return "android:switcher:" + viewPagerId + ":" + index;
}

Reference: reusing fragments in a fragmentpageradapter

Answer 4

With this function you can find the fragment by pager adapter position.

public Fragment findFragmentByPosition(int position) {
    FragmentPagerAdapter fragmentPagerAdapter = getFragmentPagerAdapter();
    return getSupportFragmentManager().findFragmentByTag(
            "android:switcher:" + getViewPager().getId() + ":"
                    + fragmentPagerAdapter.getItemId(position));
}

Sample code for v4 support api.

Answer 5

I found a slightly less gross way to get a handle on a Fragment created by a FragmentPagerAdapter. Instead of imitating the way tags are created, override instantiateItem(), get the Fragment returned by the superclass, and save the tag in TabInfo. This works for me on API >= 15, may work with lower. This still makes some assumptions about private code.

static final class TabInfo {
    private final Class<?> clss;
    private final Bundle args;
    private String tag; // ** add this

    TabInfo(Class<?> _class, Bundle _args) {
        clss = _class;
        args = _args;
    }
}


@Override
public Object instantiateItem(ViewGroup container, int position) {
    final Fragment fragment = (Fragment) super.instantiateItem(container, position);
    final TabInfo info = mTabs.get(position);
    info.tag = fragment.getTag(); // set it here
    return fragment;
}

Or in API < 16, I think instantiateItem() takes a View() instead of ViewGroup(), like this:

public Object instantiateItem(View container, int position);

Then allow a way to get the Fragment, keeping the hack contained.

public Fragment getFragment(int index) {
    return mContext.getFragmentManager().findFragmentByTag(mTabs.get(index).tag);
}

For that to work, the declaration for mContext needs to change to Activity, it's passed in as an Activity anyway:

private final Activity mContext;