How can make my ViewPager load only one page at a time ie setOffscreenPageLimit(0);

Question

I understand the lowest number I can give setOffscreenPageLimit(int) is 1. but I need to load one page at a time because memory problems.

Am i going to have to use the old style tabhost etc? or is there a way/hack I can make my viewPager load one page at a time?

My Adapter extends BaseAdapter with the ViewHolder patern.

Answer 1

I was having the same problem and I found the solution for it:

Steps:

1) First Download the CustomViewPager Class from this link.

2) Use that class as mentioned below:

In Java:

CustomViewPager mViewPager; mViewPager = (CustomViewPager) findViewById(R.id.swipePager); mViewPager.setOffscreenPageLimit(0); 

In XML:

<com.yourpackagename.CustomViewPager      xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@+id/swipePager"     android:layout_width="match_parent"     android:layout_height="match_parent"/> 

Now only one page will be loaded at once.

P.S: As per the question's requirement, I have posted the solution for Viewpager. I haven't tried the same with TabLayout yet. If I will find any solution for that I will update the answer.

In this file, KeyEventCompat is used it may not found by the android studio because KeyEnentCompat class was deprecated in API level 26.0.0 so you need to replace KeyEventCompat to event for more details you can view https://developer.android.com/sdk/support_api_diff/26.0.0-alpha1/changes/android.support.v4.view.KeyEventCompat

Answer 2

As far as I know, that is not possible when using the ViewPager. At least not, when you want your pages to be swipe-able.

The explaination therefore is very simple:

When you swipe between two pages, there is a Point when both pages need to be visible, since you cannot swipe between two things when one of those does not even exist at that point.

See this question for more: ViewPager.setOffscreenPageLimit(0) doesn't work as expected

CommonsWare provided a good explaination in the comments of his answer.