How to access a view of parent fragment from child fragment in navigation component

Question

I need to access a view of parent fragment from child fragment.

I have a graph inside a fragment (my parent fragment) and i want to access a view that present in the parent fragment from child fragment, i'm using android navigation component, it's confused me a little bit.

let say Fragment 1 implement a callback interface and child Fragment will have that callback instance in has a relation then you can access fragment one inside your child fragment. — Himeshgiri gosvami, Dec 20 '18 at 10:25
@Himeshgoswami ok i can create an interface in my Activity and Fragment1 will implement it and Fragment2 can call it from Activity using getActivity() method, it's ok but i want to directly access the view from Fragment2. — ali-star, Dec 20 '18 at 10:39
now by clicking you can call callback methods, and you can update view as needed. — Himeshgiri gosvami, Dec 20 '18 at 11:03
also have a look at my questions https://stackoverflow.com/questions/70721218/receive-fragment-result-in-navigation-component-fragment and https://stackoverflow.com/questions/70680327/toolbar-icon-handling-using-navigation-component — Taimoor Khan, Jan 16 '22 at 07:24

Anmol · Accepted Answer · 2018-12-20T17:00:15.390

18

As i read your Explanation's You Know that ChildFragment Parent is NavHostFragment and NavHostFragment's Parent is ParentFragment.

NavHostFragment navHostFragment = (NavHostFragment) getParentFragment();
Fragment parent = (Fragment) navHostFragment.getParentFragment();
parent.getView().findViewById(R.id.element_id);

I have tried is my demo Project and work's for me.

edited Dec 20 '18 at 17:00

answered Dec 20 '18 at 16:30

Anmol

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I tried so many answers but this one still works in 2022. – Amit Kundu Apr 03 '22 at 08:24
Didn't work for me ,parent of navhostfragment returns null – htafoya Jun 02 '22 at 17:11
Hi @htafoya, [this](https://stackoverflow.com/a/72482591) solved my problem, maybe you have use parentFragmentManager instead of childFragmentManager. – Shaco Jul 24 '23 at 06:34

PSK · Answer 2 · 2020-06-17T06:56:24.233

1

Using Activity:

val buttonView = (context as Activity).findViewById<View>(R.id.map_list_card_view)

Using Fragment:

val parent: Fragment? = (parentFragment as NavHostFragment).parentFragment
val buttonView = parent?.view?.findViewById<View>(R.id.map_list_card_view)

edited Jun 17 '20 at 06:56

answered Jun 12 '20 at 04:38

PSK

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Anton Sarmatin · Answer 3 · 2018-12-20T09:16:00.143

0

Try this:

ParentFragment parent = (ParentFragment) getParentFragment();
parent.getView().findViewById(R.id.your_element);

edited Dec 20 '18 at 09:16

answered Dec 20 '18 at 09:06

Anton Sarmatin

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getParentFragment() method returns NavHostFragment, not my fragment. – ali-star Dec 20 '18 at 09:11
i tried that before but got error, androidx.navigation.fragment.NavHostFragment cannot be cast to alistar.navigation.fragments.DashboardFragment – ali-star Dec 20 '18 at 10:17

score 0 · Answer 4 · answered Dec 20 '18 at 09:29

0

Try this:

public class Fragment2 extends Fragment {
    View view;
    ...
    ...

    public void setView(View view) {
        this.view = view;
    }
}

And call mFragment.setView() before calling fragment transaction. I hope this helps!

answered Dec 20 '18 at 09:29

Charan M

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i know that, but i'm using navigation component. – ali-star Dec 20 '18 at 10:14
1

This is actually bad as sending View's as Argument cause memory leak's and cause Out of memory Exception's – Anmol Dec 20 '18 at 16:20

How to access a view of parent fragment from child fragment in navigation component

4 Answers4