具有数据绑定的Android ViewPager / PagerAdapter和不执行活动视图的instantiateItem

Question

I am using Android data binding in a MVVM framework. I have a ViewPager setup with a corresponding PagerAdapter. Some of the pages may contain videos. The issue that I am having is that the instantiateItem method in the PagerAdapter always executes the next view in the PagerAdapter instead of the current view. For example say page 1 has no video, but page 2 does. When the user views page 1, the video in page 2 starts playing. Here is the instantiateItem method:

     public Object instantiateItem(ViewGroup container, int position) {
    
        LayoutInflater layoutInflater = (LayoutInflater) getApplicationContext().getSystemService(Service.LAYOUT_INFLATER_SERVICE);
    

        ViewDataBinding binding = DataBindingUtil.inflate(layoutInflater, R.layout.main_layout, null, false);
    
        Post post = posts.get(position);
        myViewModel = new PostModel(post);
    
        binding.setVariable(BR.model, myViewModel);
  
        container.addView(binding.getRoot());
    

        return binding.getRoot();
    
    }

How can I make the instantiateItem execute the current view instead of the next view? Is the issue related to setOffscreenPageLimit?

Answer 1

You can't because it's main idea of ViewPager - it preload next N pages in order to make swiping smooth. Also actually you can setup it in order to see part of next view.

I think you should use OnPageChangeListener , and manager start/stop of playing of your video when it needed here.

Btw, some advices - you can use that library in order to not write that boilerplate code at all. Here my example of usage .