How do I get the child View of a ViewPager at a given item

Question

I'll keep the question as short and simple as humanly possible.

View activeView = mViewPager.getChildAt(mViewPager.getCurrentItem());

returns the child view when the current item is 0 and 1. But if the current item is 2 it returns null . Why is that?

edit: Let me rephrase myself. How do I get the child View of a ViewPager at any given item position?

CodePrimate · Accepted Answer · 2014-03-07T11:00:52.260

32

It turns out getChildAt(int) was not the right approach. What I did was retrieve the Adapter used in the ViewPager and found my views from there:

adapter = mViewPager.getAdapter();
Fragment fragment = adapter.getItem(mViewPager.getCurrentItem());

View activeView = fragment.getView();

As already noted the viewPager will only contain the current child and adjacent children(currentItem() +/- 1) unless otherwise specified through setOffscreenPageLimit()

edited Mar 07 '14 at 11:00

answered May 12 '13 at 21:27

CodePrimate

6,646
13
48
86

23

Just a heads up to anyone coming in now, getItem is no longer a method on a pagerAdapter – Vic Vuci Jun 15 '15 at 20:53
2

@Ronnie Troj i m getting null in activeView why – Erum Jun 19 '15 at 07:56
Receiving an Illegal State Exception with this code: "Fragment MyFragment not attached to Activity". – worked Sep 27 '15 at 22:24
2

@Erum call adapter.instantiateItem(mViewPager, mViewPager.getCurrentItem()); instead of getItem – Yaroslav Dec 25 '15 at 13:50

score 7 · Answer 2 · answered May 12 '13 at 22:08

7

Your view pager adapter is holding maximum of 2 pages, i.e 2 views/fragments, the rest of them are recycled. In other case, what you did not mentioned is that you might have 2 pages/views in the ViewPager.

Please look at mViewPager.setOffscreenPageLimit()

answered May 12 '13 at 22:08

Nikola Despotoski

49,966
15
119
148

score 3 · Answer 3 · edited May 23 '17 at 12:25

3

Add tag to Viewpager return view.

Below link will help you : https://stackoverflow.com/a/20186828/1271891

edited May 23 '17 at 12:25

Community

1
1

answered Nov 25 '13 at 07:27

Raj008

3,539
2
28
26

nice one. Looks exactly for this to populate the view dynamically. Thanks!! – anand krish Jan 22 '16 at 11:14

score 0 · Answer 4 · edited May 23 '17 at 12:25

During my endeavors to find a way to decorate android views I think I defined alternative solution for th OP's problem that I have documented in my blog. I am linking to it as the code seems to be a little bit too much for including everything here.

The solution I propose:

keeps the adapter and the view entirely separated
one can easily query for a view with any index form the view pager and he will be returned either null if this view is currently not loaded or the corresponding view.

(This question is very simple to this one in which I have posted the same answer).

score -1 · Answer 5 · answered May 12 '13 at 20:48

How many child views should the be?

Also a ViewPager doesn't have all childs loaded at the same time. Only the one it is showing and the next one. You can use mViewPager.setOffscreenPageLimit() to, for example 3 or 4, to 'preload' more items into the viewpager.

How do I get the child View of a ViewPager at a given item

5 Answers5

Linked