SharedPreferences are being restored as defaults in onResume instead of the saved SharedPreferences values

Question

I have a PreferenceActivity P that stores values to SharedPreferences. This is working--I am able to make selections from the lists and the summary values are displayed correctly.

The problem is when I attempt to access the SharedPreference values within Activity A. The default values are loaded instead of the stored values. Only after I access the PreferenceActivity from Activity A do the up-to-date SharedPreference values become available to Activity A. Any suggestions on how to resolve this? Is there any option to using PreferenceManager.getDefaultSharedPreferences?

Here is the bulk of the PreferenceActivity code (I omitted the onSharedPreferenceChanged listener for brevity):

public class P extends PreferenceActivity { 
public static String KEY_PREF_show_watch_areas, KEY_PREF_time_format, KEY_PREF_date_format;
String PREF_show_watch_areas, PREF_time_format, PREF_date_format;
static SharedPreferences sharedPrefs;
Preference pref_show_watch_areas=null;
ListPreference pref_time_format=null, pref_date_format=null;

@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    sharedPrefs = PreferenceManager.getDefaultSharedPreferences( getApplicationContext() );
    KEY_PREF_show_watch_areas = getString(R.string.key_pref_show_watch_areas);
    KEY_PREF_time_format = getString(R.string.key_pref_time_format);
    KEY_PREF_date_format = getString(R.string.key_pref_date_format);
    PREF_show_watch_areas = getString(R.string.pref_show_watch_areas);
    PREF_time_format = getString(R.string.pref_time_format);
    PREF_date_format = getString(R.string.pref_date_format);

//Load up the preference items (from XML)  
    addPreferencesFromResource(R.xml.preferences);

    //DATE pref
    pref_date_format = (ListPreference) findPreference(KEY_PREF_date_format); //Set summary to user selected value
    pref_date_format.setSummary(pref_date_format.getEntry() ); 

    //TIME pref
    pref_time_format = (ListPreference) findPreference(KEY_PREF_time_format); //Set summary to show user selected value
    pref_time_format.setSummary(pref_time_format.getEntry()); 

    }

 }  // [END P]

Here is the onResume in Activity A:

  @Override
  protected void onResume() {
  super.onResume();

   SharedPreferences sharedPrefsResume = PreferenceManager.getDefaultSharedPreferences(getApplicationContext() );
   dateFormatPref = sharedPrefsResume.getString(P.KEY_PREF_date_format, "d-MMM-yy");
   timeFormatPref = sharedPrefsResume.getString(P.KEY_PREF_time_format, "h");

 } // [END onResume]

Answer 1

I've discovered and resolved the problem. I was trying to access the SharedPrefs values with uninitialized variables (e.g., P.KEY_PREF_date_format). That's the reason the default values were being returned. I've now moved the static variables to my MainActivity to ensure they are initialized. Voila. SharePreferences are working as expected now.