Exception on ListPreferences

Question

This is my first Android app and I've encountered an exception when trying to use the ListPreference. The application loads along with the preferences... but when i touch the ListPreference entry the applications "stops unexpectedly".

Settings.java

public class Settings extends PreferenceActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.addPreferencesFromResource(R.layout.settings);
    }
}

settings.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
xmlns:android="http://schemas.android.com/apk/res/android">
    <CheckBoxPreference
        android:key="chk_enabled"
        android:summary="SMS response based on settings"
        android:title="Enable"
    />
    <ListPreference
        android:title="Contacts"
        android:summary="Contacs that will be sent SMSs"
        android:key="list_contacts"
        android:defaultValue="0"
        android:entries="@array/list_entries"
        android:entryValues="@array/list_values" 
    />
</PreferenceScreen>

arrays.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="list_entries">
        <item>All</item>
        <item>WhiteList</item>
        <item>BlackList</item>
    </string-array>

    <integer-array name="list_values">
        <item>0</item>
        <item>1</item>
        <item>2</item>
    </integer-array>
</resources>

This is the logcat output:

D/AndroidRuntime( 3187): >>>>>>>>>>>>>> AndroidRuntime START <<<<<<<<<<<<<<
D/AndroidRuntime( 3187): CheckJNI is OFF
D/AndroidRuntime( 3187): --- registering native functions ---
I/jdwp    ( 3187): received file descriptor 16 from ADB
/ddm-heap( 3187): Got feature list request
I/ActivityManager(   86): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=tml.UI.main/.MainActivity }
D/AndroidRuntime( 3187): Shutting down VM
D/dalvikvm( 3187): DestroyJavaVM waiting for non-daemon threads to exit
I/ActivityManager(   86): Start proc tml.UI.main for activity tml.UI.main/.MainActivity: pid=3194 uid=10039 gids={1015}
D/dalvikvm( 3187): DestroyJavaVM shutting VM down
D/dalvikvm( 3187): HeapWorker thread shutting down
D/dalvikvm( 3187): HeapWorker thread has shut down
D/jdwp    ( 3187): JDWP shutting down net...
D/jdwp    ( 3187): +++ peer disconnected
I/dalvikvm( 3187): Debugger has detached; object registry had 1 entries
D/dalvikvm( 3187): VM cleaning up
D/dalvikvm( 3187): LinearAlloc 0x0 used 676380 of 4194304 (16%)
I/jdwp    ( 3194): received file descriptor 10 from ADB
D/ddm-heap( 3194): Got feature list request
W/Resources( 3194): Converting to string: TypedValue{t=0x10/d=0x0 a=-1}
I/ActivityManager(   86): Displayed activity tml.UI.main/.MainActivity: 977 ms (total 977 ms)
D/AndroidRuntime( 3194): Shutting down VM
W/dalvikvm( 3194): threadid=3: thread exiting with uncaught exception (group=0x4001da28)
E/AndroidRuntime( 3194): Uncaught handler: thread main exiting due to uncaught exception
E/AndroidRuntime( 3194): java.lang.NullPointerException
E/AndroidRuntime( 3194):    at android.preference.ListPreference.findIndexOfValue(ListPreference.java:169)
E/AndroidRuntime( 3194):    at android.preference.ListPreference.getValueIndex(ListPreference.java:178)
E/AndroidRuntime( 3194):    at android.preference.ListPreference.onPrepareDialogBuilder(ListPreference.java:190)
E/AndroidRuntime( 3194):    at android.preference.DialogPreference.showDialog(DialogPreference.java:291)
E/AndroidRuntime( 3194):    at android.preference.DialogPreference.onClick(DialogPreference.java:262)
E/AndroidRuntime( 3194):    at android.preference.Preference.performClick(Preference.java:811)
E/AndroidRuntime( 3194):    at android.preference.PreferenceScreen.onItemClick(PreferenceScreen.java:190)
E/AndroidRuntime( 3194):    at android.widget.AdapterView.performItemClick(AdapterView.java:284)
E/AndroidRuntime( 3194):    at android.widget.ListView.performItemClick(ListView.java:3246)
E/AndroidRuntime( 3194):    at android.widget.AbsListView$PerformClick.run(AbsListView.java:1635)
E/AndroidRuntime( 3194):    at android.os.Handler.handleCallback(Handler.java:587)
E/AndroidRuntime( 3194):    at android.os.Handler.dispatchMessage(Handler.java:92)
E/AndroidRuntime( 3194):    at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime( 3194):    at android.app.ActivityThread.main(ActivityThread.java:4203)
E/AndroidRuntime( 3194):    at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 3194):    at java.lang.reflect.Method.invoke(Method.java:521)
E/AndroidRuntime( 3194):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
E/AndroidRuntime( 3194):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
E/AndroidRuntime( 3194):    at dalvik.system.NativeStart.main(Native Method)
I/Process (   86): Sending signal. PID: 3194 SIG: 3
I/dalvikvm( 3194): threadid=7: reacting to signal 3
I/dalvikvm( 3194): Wrote stack trace to '/data/anr/traces.txt'
I/Process ( 3194): Sending signal. PID: 3194 SIG: 9
I/ActivityManager(   86): Process tml.UI.main (pid 3194) has died.
I/WindowManager(   86): WIN DEATH: Window{4341fd00 tml.UI.main/tml.UI.main.MainActivity paused=false}
W/UsageStats(   86): Unexpected resume of com.android.launcher while already resumed in tml.UI.main
W/InputManagerService(   86): Got RemoteException sending setActive(false) notification to pid 3194 uid 10039

Answer 1

I fixed it... I kept on trying and, at the end, it turns out that I cannot use an integer-array as the entryValues Source. I just changed that integer-array to a string-array and got it working.

If there's a way to use integer-array as the source for entryValues please comment.

Answer 2

I've been searching for a similar solution to what you are looking for, agreeing that you should be able to use an Integer array to read from and store an integer result.

A solution to this problem I found was at http://kvance.livejournal.com/1039349.html, which I found to be useful.

It doesn't quite solve the problem the way I was thinking or that way I think you want it to, instead you still specify your initial / selection values with a String array although when the ListPreference saves it back to the SharedPreferences it saves as an Integer instead of a String (doing the conversion when the user selects it), removing the need to have to convert it possibly many times throughout your application when accessing the preference value.