Remove item in ViewPager - android

I have ViewPager and FragmentStatePagerAdapter. I want to change dynamically content of ViewPager. For add page I use simple increase counter on 1 then call FragmentStatePagerAdapter.notifyDataSetChanged(). But if I want removing page:
destroyItem(viewPager, position, myAdapter.getItem(position));
getting error:
java.lang.IllegalStateException: Fragment MyPanel{40e80930} is not
currently in the FragmentManager

There is no destroyItem() method on ViewPager.
There is a destroyItem() method on PagerAdapter, but that is to be called by ViewPager, not by you.

Related

Using Fragments inside of Fragment

I am using 4 fragments in MainActivity with viewPager where viewPager is not scrollable, and I have four more fragments inside Second Fragment of MainActivity fragment. I am calling API in my all fragments in the onCreateView method. But when activity initialized so all fragments onCreateView method run, how to fix it because I want when the fragment is visible than my API call.
I already tried setUserVisibleHint method it's also working when activity initialized.
Should I use frame layout or anything else to fix this problem?
if i understood you good then you want to call your api when fragments are visible.
if yes then use
viewPager.addOnPageChangeListener
and onPageSelected(int position) callback then just make good condition which call you'r api
edit: changed adapter to viewPager
I think you need to put your api calls method in onResume in each fragment that will be fired when your fragment is on the top of fragments stack (Shown).

ViewPager setOffScreenPageLimit > 2 doesn't work properly

I have a ViewPager in which the first Fragment has a children fragments that is shown depending on certain conditions. whenever i set setOffscreenPageLimit() on the ViewPager > 2, Children fragments won't show up, else every thing works fine.
Any Solutions??
I was using getFragmentManager() inside the parent Fragment instead of getChildFragmentManager() while adding the child fragment which caused this strange behavior.

When is android PagerAdapter's instantiateItem called?

I have a viewpager and a pagerAdapter which inflates a custom view and adds it to the collection. After setting up the viewpager and pageradapter, I proceed to get some data which I now want to display in one of the custom views. However I observed that the pagerAdapter.instantiateItem is not being called by that time. How can I get the viewpager to start instantiateItem right away?
instantiateItem is called when the viewPager calls the getItem method. When the viewPager is first displayed, getItem is called for the currently displayed tab and the following tab.
Could you provide a code snippet for further details ?

ViewPager child view method callin automatic?

I implemented View Pager with fragment child A/B/C. To get selection of default Fragment(say A) I use mViewPager.setCurrentItem(position) and it work fine. But on this Second Fragment (B) view methods onViewCreated and setUserVisibleHint calling automatically.
Is there any way to prevent this !
You can try invoking ViewPager.setOffscreenPageLimit(0), which will no longer pre-load non-visible Fragments. The default value for the off-screen page limit is 1, so that should be the reason why the onViewCreated() and setUserVisibleHint() methods are being called for your other fragments.

OnPageChange fragment inside viewpager inside fragment called before onCreateView

I have a view pager inside a fragment. Inside the inner fragment i have to show animation when the fragment is visible. i checked this answer and tried setUserVisibleHint and OnPageChangeListener both this are called before onCreateView and gives null pointer exception. how can i find when Fragment becomes visible in ViewPager so that i can start animation.
#bill gates, viewpager is the thing, in that both page (Current page and next or previous page) both are prepare simultaneously itself, so when you slide the current page two pages are visible to user. that a awesome function of viewpager. thanks.

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