Viewpager+FragmentpagerAdapet+Fragments+Listview = insanely slow app

Question

I have a viewpager in my layout , that viewpager holds a set of 10 fragments . Each fragment has a list view , which is asynchronously populated . I m currently using FragmentPagerAdapter as adapter for the viewpager and the API calls to populate the list view is done in onCreateView of each fragment . The swipe is insanely slow and app closes itself because of the memory issues .

How to achieve smooth and responsive (viewpager+listview) like Google Play does ? Smooth swiping + good cache of list items ?

Phonetist

One more thing that i would like to add in this question can i achieve viewpager in fragment if yes then how?? – Umbilical

Answer 1

There are many ways to improve the performance of a ViewPager integrated with a ListView.

First, change the PagerAdapter from FragmentPagerAdapter to FragmentStatePagerAdapter. The difference is that you load 10 pages within the pager. And if you went through all the manager will only put the pages in onStop() therefore it will reserve space. However using FragmentStatePagerAdapter will destroy these pages but will save their instance using the onSaveInstanceState method. So when you get back it won't take much time to load and you will be saving memory.

Usually FragmentPagerAdapter is used with 3 pages or less.

The second way to improve performance (but it drains the battery faster) is adding this line to your AndroidManifest.xml under your application tag:

android:hardwareAccelerated="true"

The third way is detecting the swipe gesture. You can do this by implementing onPageChangeListener then in the implemented method onPageScrollStateChanged you check if the page is Idle then add the ListView. Otherwise, stop the use of ListView and scroll to the next page. Here is a better explanation of this point.

Hope some of these points can help you out to achieve better performance.

Luigi

Hi , if i use onPageChangeListener then each time i swipe to the page , it will make api calls and populate it . How can i cache the results . My api calls will return me a JSON . – Phonetist