StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POFragmentPagerAdapter with ViewPager and two Fragments. Go to the first from the second and update first's text
primarykey
Id
10022179
data
AcceptedAnswerId
10022665
AnswerCount
3
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2012-04-05T03:10:18.260
FavoriteCount
5
LastActivityDate
2016-12-27T19:49:36.470
LastEditDate
2017-05-23T12:16:24.547
LastEditorUserId
-1
OwnerUserId
489607
ParentId
0
PostTypeId
1
Score
8
ViewCount
9588
LastEditorDisplayName
text
Body
I'm not familiar with <code>FragmentPagerAdapter</code>, so this is going to be one of those questions that we (you) read the description critically. Structure: I have a <code>FragmentPagerAdapter</code> (code below), that will hold two fragments at a time. The first displays book excerpts, and the second a list of book titles. Goal: I want to achieve what is described in the title: the user can navigate to the second fragment in the pager, click on a title, and then I want to move the user back to the first fragment and tell the first fragment to update the text. The first fragment has a <code>triggerRefresh</code> method for that. Code: I believe my problem happens because of the way <code>FragmentPagerAdapter</code> reuses/creates the Fragments (which I don't understand). This is my class: <pre><code>static class MyFragmentPagerAdapter extends FragmentPagerAdapter { public MyFragmentPagerAdapter(FragmentManager fm) { super(fm); } @Override public int getCount() { return NUM_ITEMS; } @Override public Fragment getItem(int position) { switch(position) { case 0: return new ExcerptsFragment(); case 1: return new BookListFragment(); default: throw new IllegalArgumentException("not this many fragments: " + position); } } } </code></pre> This is how I created the relevant members: <pre><code>ViewPager mViewPager = (ViewPager) findViewById(R.id.pager); MyFragmentPagerAdapter mFragmentPagerAdapter = new MyFragmentPagerAdapter(getSupportFragmentManager()); mViewPager.setAdapter(mFragmentPagerAdapter); </code></pre> And this is what I've tried elsewhere in my Activity, when I receive the callback from the book titles Fragment with the title selected: <pre><code>mViewPager.setCurrentItem(0); // back to excerpts screen page. It's OK. // Here's the problem! How to identify the fragment 0 // to ExcerptsFragment and call its triggerRefresh()?!? </code></pre> Series of problems: Calling the adapter's <code>getView()</code> won't work because it will return a new instance of <code>ExcerptsFragment</code>, which is not the one currently attached (as expected, throws the exception). I've seen many people here (<a href="https://stackoverflow.com/a/9214669/489607">example</a>) just storing fragments in the <code>getView()</code>. Is that right? Because by looking at the official examples, seems like an anti-pattern to me (defeat the automatic reference by holding the items). And that is also the opinion <a href="https://stackoverflow.com/a/7098081/489607">here</a> and <a href="https://stackoverflow.com/a/9759024/489607">here</a> (and looks right to me). Any suggestions? I wouldn't be surprised if I'm not understanding all of this one bit...
Tags
<android><android-fragments><android-viewpager><updating><fragmentpageradapter>
Title
FragmentPagerAdapter with ViewPager and two Fragments. Go to the first from the second and update first's text
singulars
PostAcceptedAnswerId
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USCommunity
UserOwnerUserId
1. USdavidcesarino
plurals
PostLinksPostIdRelatedPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
2. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
3. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostLinksRelatedPostIdPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.