问Android ListPreference

EN

    PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >

        <PreferenceCategory
           <ListPreference
                android:key="language"
                android:title="@string/language"
                android:summary="@string/select_language"
                android:defaultValue="en"
                android:entries="@array/languages"
                android:entryValues="@array/languagesValues"
                />

    </PreferenceScreen>

    <?xml version="1.0" encoding="utf-8"?>
    <resources>

        <string-array name="languages">
            <item name="english">English</item>
            <item name="french">French</item>
        </string-array>

        <string-array name="languagesValues">
            <item name="english">en</item>
            <item name="french">fr</item>
        </string-array>

    </resources>

        public class Settings extends PreferenceActivity {

            Locale myLocale;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(R.xml.preferences);

            Preference langPreference = getPreferenceScreen().findPreference(
                    "language");
            langPreference.setOnPreferenceChangeListener(languageChangeListener);
        }

        Preference.OnPreferenceChangeListener languageChangeListener = new OnPreferenceChangeListener() {

            @Override
            public boolean onPreferenceChange(Preference preference, Object newValue) {

                switch (newValue.toString()) {
                case "en":
                    setLocale("en");
                     Toast.makeText(getApplicationContext(), "Locale in English!", Toast.LENGTH_LONG).show();
                    break;

                case "fr":
                    setLocale("fr");
                     Toast.makeText(getApplicationContext(), "Locale in French!", Toast.LENGTH_LONG).show();
                    break;
                }
                return false;
            }
        };

        //* manually changing current locale/
        public void setLocale(String lang) { 
            myLocale = new Locale(lang); 
            Resources res = getResources(); 
            DisplayMetrics dm = res.getDisplayMetrics(); 
            Configuration conf = res.getConfiguration(); 
            conf.locale = myLocale; 
            res.updateConfiguration(conf, dm); 
            Intent refresh = new Intent(this, Settings.class); 
            finish();
            startActivity(refresh); 
        } 

    }