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POAndroid - PagerAdapter not saving RadioButton's state
 

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  1. POAndroid - PagerAdapter not saving RadioButton's state
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    <p>I have a very peculiar problem. I understand that while in the foreground the member variables of an Activity remain untouched (don't need saving to persist). Now, I have a <code>PagerAdapter</code> that represents a quiz with a question and three answers. I've made various objects to represent the question and answers.</p> <p>A <code>Question</code> always has a list of exactly 3 <code>Answer</code>'s. This is how I do it: (note: some code was left out for readability)</p> <pre><code>public class QuizPagerAdapter { List&lt;Question&gt; questionList; Context context; public QuizPagerAdapter (List&lt;Question&gt; list, Context ctx) { questionList = list; context = ctx; } @Override public Object instantiateItem (View pager, int position) { // Create various views (ScrollView, LinearLayout, etc) final Question q = questionList.get(position); RadioGroup group = new RadioGroup(context); for (int i = 0; i &lt; 3; i++) { Answer a = q.getAnswer(i); RadioButton rb = new RadioButton(context); rb.setId(i); rb.setText(a.getText()); rb.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { RadioButton btn = (RadioButton) v; q.unselectAll(); // unselects all Answer's q.getAnswer(btn.getId()).setSelected(true); } }); if (a.isSelected()) rb.setChecked(true); } return view; } } </code></pre> <p>When I use this in my Activity, I get a nice list of Questions with three Answers. Now, when I select one Answer, the RadioButton is checked. OK, now, I scroll to the next Question and check that one, then go back to the previous Question and there the answer I checked in the first place is now <strong>not</strong> checked.</p> <p>Now, this doesn't always happen, it happens sometimes, but that sometimes is enough that it can cause a problem. The Activity is never placed in the background.</p> <p>I understand that Android will destroy Views in the PagerAdapter to conserve memory, thus destroying the RadioButton, this is why I have this snippet:</p> <pre><code>if (a.isSelected()) rb.setChecked(true); </code></pre> <p>But it is still happening. I've tried logging everything, debugging but I cant seem to get to the source of the problem. Maybe someone here has come across a similar problem.</p> <p>Any help is appreciated, Thank you in advance!</p>
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