Why does getActivity of my fragment returns null?

Question

I currently have a thread in my main Activity do download stuff frow web and I then need to update the Fragments inside a ViewPager after download finished.

The download is handled by a service and broadcast an Intent when finished.

So, basically, my code in my main Activity is:

public class MyBroadcastReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        ((PositionFragment)mPagerAdapter.getItem(0)).updateUI();
    }
}

and my PositionFragment:

public void updateUI() {
    mActivity = getActivity();

I really don't get how this can be null. This really souds simple, but I must be missing something!

Any idea?

Edit: my Adapter:

public class PageAdapter extends FragmentPagerAdapter {
    private List<Fragment> fragments;

    public PageAdapter(FragmentManager fm, List<Fragment> fragments) {
        super(fm);
        this.fragments = fragments;
    }

    @Override
    public Fragment getItem(int position) {
        return this.fragments.get(position);
    }

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

    @Override
    public CharSequence getPageTitle(int position) {
        return titles[position];
    }
}

As you can see in my Adapter, the getItem returns the created Fragment that exists! — Waza_Be, Jun 08 '13 at 19:40
It always happens, I have set a code in the onResume of the Fragment to broadcast the Intent it if data is too old. So the Activity+Fragment have just been set in background and then resumed — Waza_Be, Jun 08 '13 at 19:46
`getActivity()` is returning null because the fragment did not get attached to the Activity yet. Where are you calling `updateUI()`? In `onCreateView()`? — Ahmad, Jun 08 '13 at 19:51
Possible duplicate of [getActivity() returns null in Fragment function](http://stackoverflow.com/questions/6215239/getactivity-returns-null-in-fragment-function) — rds, Nov 12 '15 at 19:17
Look for [this link](http://stackoverflow.com/a/27678112/1252158), it might help — Summved Jain, Feb 15 '17 at 13:59

score 6 · Accepted Answer · edited May 23 '17 at 12:01

6

Your fragment has probably been detached from the activity. See this link for more details.

edited May 23 '17 at 12:01

Community

1
1

answered Jun 08 '13 at 19:48

Neoh

15,906
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Sound like a start, but how should I access the Fragment in the Adapter with FragmentManager, like suggested in the answer.. I will try this other solution that looks nice: http://stackoverflow.com/a/15261142/327402 – Waza_Be Jun 08 '13 at 19:59

score 0 · Answer 2 · answered Jun 08 '13 at 19:51

0

You can call getActivity() only after fragment's onAttach method is called. I believe, that's the issue here.

answered Jun 08 '13 at 19:51

asenovm

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4

This code is called after the onResume, so I strongly belive that onAttach was called before ;-) – Waza_Be Jun 08 '13 at 19:54

Why does getActivity of my fragment returns null?

2 Answers2