Question

I’m trying to run an example I found it on a book about the ListView. As the book stated, I created the string-array in string.xml file and the layout of the ListView is in list_item.xml inside res->layout folder.

The problem is that, the app crashes when I run the activity. Can any one tell me where the mistake is?

Code1:

public class ListViewTestActivity extends ListActivity {
/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    String[] c = getResources().getStringArray(R.array.cities);
    setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, c));
    }}

string.xml

<resources>

<string name="hello">Hello World, ListViewTestActivity!</string>
<string name="app_name">ListViewTest</string>

<string-array
        name="cities">
    <item>Bath</item>
    <item>Birmingham</item>
    <item>Bradford</item>
    <item>Brighton</item>
    <item>Bristol</item>
    <item>Cambridge</item>
    <item>Canterbury</item>
</string-array>

list_item.xml:

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:textSize="28dip">
    </TextView>


</LinearLayout>

LogCat:

    05-05 22:45:16.018: E/ArrayAdapter(648): You must supply a resource ID for a TextView
05-05 22:45:16.048: E/AndroidRuntime(648): FATAL EXCEPTION: main
05-05 22:45:16.048: E/AndroidRuntime(648): java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:347)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.AbsListView.obtainView(AbsListView.java:1430)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ListView.makeAndAddView(ListView.java:1745)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ListView.fillDown(ListView.java:670)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ListView.fillFromTop(ListView.java:727)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ListView.layoutChildren(ListView.java:1598)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.AbsListView.onLayout(AbsListView.java:1260)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.view.View.layout(View.java:7175)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.view.View.layout(View.java:7175)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1254)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1130)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.LinearLayout.onLayout(LinearLayout.java:1047)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.view.View.layout(View.java:7175)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.FrameLayout.onLayout(FrameLayout.java:338)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.view.View.layout(View.java:7175)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.view.ViewRoot.performTraversals(ViewRoot.java:1140)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.os.Looper.loop(Looper.java:130)
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.app.ActivityThread.main(ActivityThread.java:3683)
05-05 22:45:16.048: E/AndroidRuntime(648):  at java.lang.reflect.Method.invokeNative(Native Method)
05-05 22:45:16.048: E/AndroidRuntime(648):  at java.lang.reflect.Method.invoke(Method.java:507)
05-05 22:45:16.048: E/AndroidRuntime(648):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-05 22:45:16.048: E/AndroidRuntime(648):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-05 22:45:16.048: E/AndroidRuntime(648):  at dalvik.system.NativeStart.main(Native Method)
05-05 22:45:16.048: E/AndroidRuntime(648): Caused by: java.lang.ClassCastException: android.widget.LinearLayout
05-05 22:45:16.048: E/AndroidRuntime(648):  at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:340)

Answer 1

If you use that particular layout for the row item then assign an id to the TextView and pass that in the constructor of the adapter to let the adapter know where to place the data:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<TextView
    android:id="@+id/text"  
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:textSize="28dip">
</TextView>

and in your activity:

setListAdapter(new ArrayAdapter<String>(this, R.layout.list_item, R.id.text, c));