Is it possible to access the current Fragment being viewed by a ViewPager?

I have an app with a ViewPager and three Fragments. I'm trying to figure out how to get the current Fragment being viewed so I can get at its arguments.

I have an OnPageChangeListener grabbing the current page index, but

ViewPager.getChildAt(int position);

returns a View. What's the relationship between this View and the current Fragment?

Solution 1:

I finally found an answer that worked for me. Basically, you can access the fragment for a viewPager page by using the tag "android:switcher:"+R.id.viewpager+":0".

Solution 2:

I've solved this problem the other way round. Instead of searching for the fragment from the activity, I'm registering the Fragment during it's onAttach() method at it's owner activity and de-registering it in the onStop() method. Basic Idea:

Fragment:

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try{
        mActivity = (IMyActivity)activity;
    }catch(ClassCastException e){
        throw new ClassCastException(activity.toString() +" must be a IMyActivity");
    }

    mActivity.addFragment(this);
}

@Override
public void onStop() {
    mActivity.removeFragment(this);
    super.onStop();
}

IMyActivity:

public interface IFriendActivity {
    public void addFragment(Fragment f);
    public void removeFragment(Fragment f); 
}

MyActivity:

public class MyActivity implements IMyActivity{

    [...]

    @Override
    public void addFragment(Fragment f) {
        mFragments.add(f);
    }

    @Override
    public void removeFragment(Fragment f) {
        mFragments.remove(f);
    }

}

Solution 3:

Edit - Don't do this. If you're tempted to, read the comments for why it's a bad idea.

On the odd-chance you're still trying to solve this problem:

Extend FragmentPagerAdapter. In the constructor, build the Fragments you need and store them in a List (array/ArrayList) of Fragments.

private final int numItems = 3;
Fragment[] frags;

public SwipeAdapter (FragmentManager fm) {
    super(fm);

    //Instantiate the Fragments
    frags = new Fragment[numItems];

    Bundle args = new Bundle();
    args.putString("arg1", "foo");

    frags[0] = new MyFragment();
    frags[1] = new YourFragment();
    frags[2] = new OurFragment();
    frags[2].setArguments(args);
}

Then for getItem(int position), you can do something like

public Fragment getItem(int position) {
    return frags[position];
}

I'm not sure if this is the generally accepted way of doing it but it worked for me.

Edit

This is really not a good way to go. If you plan on handling orientation changes or your app going into the background, then this will probably break your code. Please read the comments below this answer for more info. Rather use @James 's answer

Solution 4:

Yes, it's possible if you are using FragmentStatePagerAdapter.

ViewPager vp;
//...
YourFragment fragment = (YourFragment) adapter.instantiateItem(vp, vp.getCurrentItem());