Question

I got some troubles with a SharedPreferences. It looks like they are not shared trough my different activities (for example my preferences are saved in my PreferencesActivity but not available from my other activities)

Here is the code for my PrefencesActivity :

public class SettingsActivity extends SherlockPreferenceActivity {

    public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            // Creating the ActionBar
            ActionBar mActionBar = getSupportActionBar();
            mActionBar.setHomeButtonEnabled(true);
            mActionBar.setDisplayShowHomeEnabled(true);
            mActionBar.setDisplayHomeAsUpEnabled(true);

            // Getting the preferences
            SharedPreferences preferences = getApplicationContext().getSharedPreferences("PreferencesFile", getApplicationContext().MODE_PRIVATE);
            getPreferenceManager().setSharedPreferencesName("PreferencesFiles");
            addPreferencesFromResource(R.xml.preferences);
    }
}

The preferences.xml file :

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
        xmlns:android="http://schemas.android.com/apk/res/android">

    <PreferenceCategory
            android:title="Informations utilisateur">

        <EditTextPreference
                android:key="id_utilisateur"
                android:title="Identifiant"
                android:summary="Votre identifiant Hangin\'Around"
                android:dialogTitle="Identifiant Hangin\'Around :" />

        <EditTextPreference
                android:key="mdp_utilisateur"
                android:title="Mot de passe"
                android:summary="Votre mot de passe sur Hangin\'Around"
                android:dialogTitle="Mot de passe Hangin\'Around :" />

    </PreferenceCategory>

    <PreferenceCategory
            android:title="Alerte de chute">
        <EditTextPreference
                android:key="num_contact"
                android:title="Numéro à contacter"
                android:summary="Le numéro auquel un SMS sera envoyé en cas de chute"
                android:dialogTitle="Numéro à contacter en cas de chute :" />

        <EditTextPreference
                android:key="nom"
                android:title="Nom présenté"
                android:summary="Le nom auquel vous serez présenté à votre contact"
                android:dialogTitle="Nom présenté :" />

        <CheckBoxPreference
                android:key="confirm"
                android:title="Confirmation de le chute"
                android:summary="Affichera un message vous demandant de confirmer l'envoi d'un message d'alerte de chute" />
     </PreferenceCategory>

    <PreferenceCategory
            android:title="Gestion des modèles de mouvement">

        <PreferenceScreen
                android:title="Enregistrer un nouveau modèle">
            <intent android:action=".EnregistrementActivity"/>
        </PreferenceScreen>

        <PreferenceScreen
                android:title="Gérer les modèles de mouvement">
            <intent android:action=".GestionModelesActivity"/>
        </PreferenceScreen>

    </PreferenceCategory>

</PreferenceScreen>

And here’s how I get the preferences in my activities :

protected void onCreate(Bundle savedInstanceState) {
    //creating the activity and stuffs

    // Getting my preferences
    SharedPreferences preferences = getApplicationContext().getSharedPreferences("PreferencesFile", getApplicationContext().MODE_PRIVATE);
    numContact = preferences.getString("num_contact", null);
    nomUser = preferences.getString("nom", null);
    confirm = preferences.getBoolean("confirm", false);
    modeleChute = preferences.getString("modele_chute", null);

    Log.d(TAG, "numContact = " + numContact + " - nomUser = " + nomUser + " - modeleChute = " + modeleChute);
}

And the log shows (modeleChute comes from another activity) :

01-14 17:04:40.444: D/MainActivity(13277): numContact = null - nomUser = null - modeleChute = Immobile

Am I doing something wrong ? (I guess so)

Answer 1

Change

SharedPreferences preferences = getApplicationContext().getSharedPreferences("PreferencesFile", getApplicationContext().MODE_PRIVATE);

to:

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context)

update: The reason is the default implementation of the xml preferences will save to your defaultSharedPreferences rather than the one you defined. You can use
setDefaultValues to change the default if its really needed.