When should I use ViewPager?

Charlotte SmithMiscellaneous

When should I use ViewPager? ViewPager in Android is a class that allows the user to flip left and right through pages of data. This class provides the functionality to flip pages in app. It

When should I use ViewPager?

ViewPager in Android is a class that allows the user to flip left and right through pages of data. This class provides the functionality to flip pages in app. It is a widget found in the support library. To use it you’ll have to put the element inside your XML layout file that’ll contain multiple child views.

How do I refresh my ViewPager adapter?

Reload the data and call pageAdapter. notifyDataSetChanged() Now, for each of the affected pages, see if the page is active by using pager. getChildAt(i) – this tells you if you have a view.

How do I reset my ViewPager?

It works if you do the following:

  1. invalidate the viewPager to invalidate the cache.
  2. call notifyDataSetChanged() to tell the adapter that there have been changes and it has to refresh the Fragments.
  3. override getItemPosition in your FragmentStatePagerAdapter in order to have all of your Fragments refreshed.

What is difference between ViewPager and ViewPager2?

ViewPager2 is an improved version of the ViewPager library that offers enhanced functionality and addresses common difficulties with using ViewPager . If your app already uses ViewPager , read this page to learn more about migrating to ViewPager2 .

What can I use instead of FragmentPagerAdapter?

Technically, ViewPager is not deprecated, but the two concrete PagerAdapter implementations — FragmentPagerAdapter and FragmentStatePagerAdapter — are deprecated. Ideally, switch to something else, such as ViewPager2 or the pager composable in Accompanist.

What is the difference between FragmentPagerAdapter and FragmentStatePagerAdapter?

As I explained FragmentPagerAdapter stores the whole fragment in memory, and could increase a memory overhead if a large amount of fragments are used in ViewPager. In contrary its sibling, FragmentStatePagerAdapter only stores the savedInstanceState of fragments, and destroys all the fragments when they lose focus.

Is ViewPager deprecated?

How can make my ViewPager load only one page at a time?

For loading only the visible fragment you have to set the behaviour to BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT in the viewpager adapter. ie; in the Constructor. And for handling the fragment use onResume() method in the fragment. In this way you can load only one fragment at a time in the viewpager.

What is PagerAdapter?

ViewPager associates each page with a key Object instead of working with Views directly. This key is used to track and uniquely identify a given page independent of its position in the adapter. A call to the PagerAdapter method startUpdate(ViewGroup) indicates that the contents of the ViewPager are about to change.

When should I use FragmentPagerAdapter?

Therefore it is advised to use FragmentPagerAdapter only when there are low number of fragments for ViewPager. It would be even better if the fragments are static, since they would not be having large amount of objects whose instances would be stored.

What can I use instead of FragmentStatePagerAdapter?