android viewpager change adapter

问题

I'm developing an app with a ViewPager for lateral scrolling tables, sometimes i need to change the adapter to load a different set of tables. I've tried to do the following:

mViewPager.setAdapter(new pagerAdapterPushed(getSupportFragmentManager()));
mViewPager.getAdapter().notifyDataSetChanged();
indicator.setViewPager(mViewPager);
indicator.invalidate();
mViewPager.invalidate();

but it always reload the previous data. Isn't it possibile to change the adapter of a ViewPager?

回答1:

Exactly like my APP doing...

For change ViewPagerAdapter, what I did is :

Clear all Fragments inside current adapter
Set current adapter to null

Assign new adpater for ViewPager

/* Clear all Fragments inside current adapter */
public class MyPagerAdapter extends FragmentPagerAdapter
{
  private ArrayList<Fragment> fragments=new ArrayList<Fragment>();
  //...some stuff

  public void clearAll() //Clear all page
  {
    for(int i=0; i<fragments.size(); i++)
    fragMan.beginTransaction().remove(fragments.get(i)).commit();
    fragments.clear();
  }
}

/* Set current adapter to null */
Constants.VP.removeAllViews();
Constants.VP.setAdapter(null);

/* Assign new adpater for ViewPager */
Constants.PAGER=new MyewPagerAdapter(getSupportFragmentManager());
Constants.VP.setAdapter(Constants.PAGER);

Hope it helps~

回答2:

You need to override public int getItemPosition (Object object) in pager adapter. For every element in the viewpager, you need to return POSITION_UNCHANGED (if it is still in the pager) or POSITION_NONE (if it was removed). Otherwise the view pager won't know something has changed. I wouldn't recommend setting a new adapter, just clearing out the data in the old one.

回答3:

I see that @RRTW way worked for some people but it did not do the trick for me (although it was close). Without 'commitNow()' instead of regular 'commit()' it would not work properly. I did something like that:

    private fun changePagerAdapter(newAdapter: PagerAdapter) {
    val transaction = supportFragmentManager.beginTransaction()
    supportFragmentManager.fragments.forEach {
        transaction.remove(it)
    }
    transaction.commitNow()
    view_pager.adapter = newAdapter
}

回答4:

I found a very simple option, I do not know if it's right or wrong, but you can just re-set the adapter

mViewPager.setAdapter(mSectionsPagerAdapter);

It's example for google example project Tabbed Activity for button FloatingActionButton

回答5:

Add this to view pager to reload for next fragment:

viewPager.setCurrentItem()

来源：https://stackoverflow.com/questions/12783571/android-viewpager-change-adapter

标签

android

adapter

android-viewpager