Update data in ListFragment as part of ViewPager

Question

I\'m using the v4 compatibility ViewPager in Android. My FragmentActivity has a bunch of data which is to be displayed in different ways on different pages in my ViewPager.

Answer 1

You can copy FragmentPagerAdapter and modify some source code, add getTag() method

for example

public abstract class AppFragmentPagerAdapter extends PagerAdapter {
private static final String TAG = "FragmentPagerAdapter";
private static final boolean DEBUG = false;

private final FragmentManager mFragmentManager;
private FragmentTransaction mCurTransaction = null;
private Fragment mCurrentPrimaryItem = null;

public AppFragmentPagerAdapter(FragmentManager fm) {
    mFragmentManager = fm;
}


public abstract Fragment getItem(int position);

@Override
public void startUpdate(ViewGroup container) {
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
    if (mCurTransaction == null) {
        mCurTransaction = mFragmentManager.beginTransaction();
    }

    final long itemId = getItemId(position);


    String name = getTag(position);
    Fragment fragment = mFragmentManager.findFragmentByTag(name);
    if (fragment != null) {
        if (DEBUG) Log.v(TAG, "Attaching item #" + itemId + ": f=" + fragment);
        mCurTransaction.attach(fragment);
    } else {
        fragment = getItem(position);
        if (DEBUG) Log.v(TAG, "Adding item #" + itemId + ": f=" + fragment);

        mCurTransaction.add(container.getId(), fragment,
                getTag(position));
    }
    if (fragment != mCurrentPrimaryItem) {
        fragment.setMenuVisibility(false);
        fragment.setUserVisibleHint(false);
    }

    return fragment;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    if (mCurTransaction == null) {
        mCurTransaction = mFragmentManager.beginTransaction();
    }
    if (DEBUG) Log.v(TAG, "Detaching item #" + getItemId(position) + ": f=" + object
            + " v=" + ((Fragment) object).getView());
    mCurTransaction.detach((Fragment) object);
}

@Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
    Fragment fragment = (Fragment) object;
    if (fragment != mCurrentPrimaryItem) {
        if (mCurrentPrimaryItem != null) {
            mCurrentPrimaryItem.setMenuVisibility(false);
            mCurrentPrimaryItem.setUserVisibleHint(false);
        }
        if (fragment != null) {
            fragment.setMenuVisibility(true);
            fragment.setUserVisibleHint(true);
        }
        mCurrentPrimaryItem = fragment;
    }
}

@Override
public void finishUpdate(ViewGroup container) {
    if (mCurTransaction != null) {
        mCurTransaction.commitAllowingStateLoss();
        mCurTransaction = null;
        mFragmentManager.executePendingTransactions();
    }
}

@Override
public boolean isViewFromObject(View view, Object object) {
    return ((Fragment) object).getView() == view;
}

@Override
public Parcelable saveState() {
    return null;
}

@Override
public void restoreState(Parcelable state, ClassLoader loader) {
}


public long getItemId(int position) {
    return position;
}

private static String makeFragmentName(int viewId, long id) {
    return "android:switcher:" + viewId + ":" + id;
}

protected abstract String getTag(int position);
}

then extend it, override these abstract method,don't need to be afraid of Android Group change

FragmentPageAdapter source code in the future

 class TimeLinePagerAdapter extends AppFragmentPagerAdapter {


    List list = new ArrayList();


    public TimeLinePagerAdapter(FragmentManager fm) {
        super(fm);
        list.add(new FriendsTimeLineFragment());
        list.add(new MentionsTimeLineFragment());
        list.add(new CommentsTimeLineFragment());
    }


    public Fragment getItem(int position) {
        return list.get(position);
    }

    @Override
    protected String getTag(int position) {
        List tagList = new ArrayList();
        tagList.add(FriendsTimeLineFragment.class.getName());
        tagList.add(MentionsTimeLineFragment.class.getName());
        tagList.add(CommentsTimeLineFragment.class.getName());
        return tagList.get(position);
    }


    @Override
    public int getCount() {
        return list.size();
    }


}