Question

I have an inner class to create and show a simple list dialog.

private static class DisplayListDialogFragment extends DialogFragment 
{
    List<String> list;
    OnClickListener clickListener;

    private static DisplayListDialogFragment newInstance(List<String> list, String title, OnClickListener clickListener)
    {
        DisplayListDialogFragment dldf = new DisplayListDialogFragment();
        dldf.list = (List<String>)list;
        dldf.clickListener = clickListener;
        Bundle bundle = new Bundle();
        bundle.putString("title", title);
        dldf.setArguments(bundle);
        return dldf;
    }

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState)
    {
        ArrayAdapter<String> ad = new ArrayAdapter<String>(getActivity(), R.id.simpleListItem, this.list);
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setTitle(R.string._select_display)
               .setSingleChoiceItems(ad, 1, this.clickListener);
        return builder.create();
    }
}

The resources referenced are declared in the strings file

    <string name="_select_display">Select Display</string>

and a small file called simple_list.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/simpleListItem"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:textAppearance="?android:attr/textAppearanceMedium"
/>

The app blows up somewhere in the depths of the resource inflater at the line

return builder.create();

Stack trace is

11-12 17:21:01.664: E/AndroidRuntime(1335): android.content.res.Resources$NotFoundException: Resource ID #0x7f040052 type #0x12 is not valid
11-12 17:21:01.664: E/AndroidRuntime(1335):     at android.content.res.Resources.loadXmlResourceParser(Resources.java:1874)
11-12 17:21:01.664: E/AndroidRuntime(1335):     at android.content.res.Resources.getLayout(Resources.java:731)
11-12 17:21:01.664: E/AndroidRuntime(1335):     at android.view.LayoutInflater.inflate(LayoutInflater.java:318)
11-12 17:21:01.664: E/AndroidRuntime(1335):     at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:332)
11-12 17:21:01.664: E/AndroidRuntime(1335):     at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)

Resource ID is defined in R.java as

        public static final int simpleListItem=0x7f040052

(i.e. the TextView declared in the simple_list.xml file above)

Can anybody see what’s wrong? I’m scratching my head at the moment.

Thanks

Andrew

Answer 1

Have a look at the documentation for the specific ArrayAdapter constructor you’re calling:

public ArrayAdapter (Context context, int textViewResourceId, List<T> objects)

In particular, it explains the second parameter parameter:

textViewResourceId – The resource ID for a layout file containing a TextView to use when instantiating views.

In other words, you’re currently passing in a wrong ID type (that’s what the LogCat error says too). Rather than supplying a TextView ID within a layout file, you should supply the ID of the layout file. Think about it: how would Android know where to inflate your TextView from if you don’t mention the layout?

Change creating the ArrayAdapter to:

ArrayAdapter<String> ad = new ArrayAdapter<String>(getActivity(), R.layout.simple_list, this.list);

Alternatively, pass in both the layout and TextView ID:

ArrayAdapter<String> ad = new ArrayAdapter<String>(getActivity(), R.layout.simple_list, R.id.simpleListItem, this.list);

PS: I do agree that the documentation may lead to some confusion as the meaning of the textViewResourceId parameter differs with the various constructors.