Question

I’ve got an app that has a handheld layout.xml and a tablet layout.xml. Inside the layout.xml a fragment is declared like this:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="horizontal"
              android:layout_width="fill_parent"
              android:layout_height="fill_parent"
              android:paddingTop="2dp"
              android:paddingBottom="2dp">

<fragment class="com.example.MyFrag"
          android:id="@+id/myFrag"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"/>
</LinearLayout>

For the same of keeping things simple, let’s say that this layout.xml is identical in res/layout and res/layout-large.

In my main activity, I reference this fragment like this:

final myFrag = (MyFrag) getSupportFragmentManager().findFragmentById(R.id.myFrag);

This works fine for the tablet, but when I try to run on handheld, myFrag is null. After a little playing around I found that if I change the name in the handheld layout.xml to myFrag2 and search for that name instead, it works. What confuses me is that according to the Android documentation, I should be able to reuse this id:

http://developer.android.com/guide/topics/ui/declaring-layout.html#id

Am I doing something wrong? I really don’t want to have to write code to test whether myFrag is null and then try loading the handheld name instead…

Answer 1

Turns out this is a non-question. I couldnt say exactly why but it appears R was not being properly regenerated. I wiped it out and regenerated it and all was well with the world, so it looks like there’s nothing special going on afterall.