Retrieve a Fragment from a ViewPager

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逝去的感伤
逝去的感伤 2020-11-21 11:13

I\'m using a ViewPager together with a FragmentStatePagerAdapter to host three different fragments:

  • [Fragment1]
  • [Fragment2]<
23条回答
  •  慢半拍i
    慢半拍i (楼主)
    2020-11-21 11:46

    You don't need to call getItem() or some other method at later stage to get the reference of a Fragment hosted inside ViewPager. If you want to update some data inside Fragment then use this approach: Update ViewPager dynamically?

    Key is to set new data inside Adaper and call notifyDataSetChanged() which in turn will call getItemPosition(), passing you a reference of your Fragment and giving you a chance to update it. All other ways require you to keep reference to yourself or some other hack which is not a good solution.

    @Override
    public int getItemPosition(Object object) {
        if (object instanceof UpdateableFragment) {
            ((UpdateableFragment) object).update(xyzData);
        }
        //don't return POSITION_NONE, avoid fragment recreation. 
        return super.getItemPosition(object);
    }
    

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