Question

I have a main Activity A, in which I create a background thread to load data from db. After the loading is done, I want to update the list which might have been already shown in a child activity B (If user has navigated to B in the meanwhile). If user hasnt yet navigated to B, its not an issue.

But how to update B’s list once thread in A has finished?

B is a child of A.

Thanks,

Answer 1

Thanks Imran,

I handled it by creating an IntentService in a separate class (inner class was not working), and start it from A. After work is done I fire a BroadCast from the IntentService which B’s broadcastreceiver is listening. It updates the list eventually.

Here is the code:

In class A, just start the IntentService in for ex OnCreate():

Intent contactIntent = new Intent(this, ContactLoaderService.class);
        startService(contactIntent);    

Create IntentService like (in a separate class):

public class ContactLoaderService extends IntentService {
    public ContactLoaderService() {
        super("ContactLoaderService");
    }

    @Override
    protected void onHandleIntent(Intent arg0)
    {
        populateContacts();

        Intent broadcastIntent = new Intent();
        broadcastIntent.setAction(ContactsResponseReceiver.ACTION_RESP);
        broadcastIntent.addCategory(Intent.CATEGORY_DEFAULT);
        sendBroadcast(broadcastIntent);
    }
}

In class B I create an inner class which just updates the list like:

public class ContactsResponseReceiver extends BroadcastReceiver {
    public static final String ACTION_RESP = "com.a.b.c.ContactsLoaded";

    @Override
    public void onReceive(Context context, Intent intent) {
        mCurrentAdapter.notifyDataSetChanged();
    }
}

In B, dont forget to register the receiver. In B’s onCreate() method:

IntentFilter filter = new IntentFilter(ContactsResponseReceiver.ACTION_RESP);
filter.addCategory(Intent.CATEGORY_DEFAULT);
receiver = new ContactsResponseReceiver();
registerReceiver(receiver, filter);

And the usual service tag in AndroidManifest.xml

<service android:name="com.a.b.c.ContactLoaderService"> </service>