Question

Okay I started to implement this horrible code from Google’s android. The OnSharedPreferenceChangeListener is not being called. This is my code, can you please advice?

Class definition:

private SharedPreferences sPrefs;
private PreferenceChangedListener prefsChangedListener;

I have a private inner class:

private class PreferenceChangedListener implements
        OnSharedPreferenceChangeListener {

    public void onSharedPreferenceChanged(
            SharedPreferences sharedPreferences, String key) {
        if (key == "highThreshold") {
            try {
                highThreshold = Float.parseFloat(sharedPreferences
                        .getString(key, "0"));
            } catch (Exception e) {
            }
        }
    }
}

Tried te following code in OnResume and to register the listener after the ‘Voorkeuren’ preferenceactivity is started. Both fail.

sPrefs = getPreferences(MODE_PRIVATE);
prefsChangedListener = new PreferenceChangedListener(); 
sPrefs.registerOnSharedPreferenceChangeListener(prefsChangedListener );

I defined a class Voorkeuren which extends PreferenceActivity

public class Voorkeuren extends PreferenceActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_voorkeuren, menu);
        return true;
    }
}

Which I open as following:

Intent intent = new Intent(getBaseContext(),Voorkeuren.class);
startActivity(intent);

The class shows up fine, and stores the values between sessions. But my application should not be polling if settings chagned. Any ideas? I have red something about an SharedPreferences.Editor but I am not sure how it is related.

Answer 1

Not sure what your question is and what is desired.

But there is one change that you need to do. Replace this in onResume

sPrefs = getPreferences(MODE_PRIVATE);
prefsChangedListener = new PreferenceChangedListener(); 
sPrefs.registerOnSharedPreferenceChangeListener(prefsChangedListener );

to

sPrefs = PreferenceManager.getDefaultSharedPreferences(this);;
prefsChangedListener = new PreferenceChangedListener(); 
sPrefs.registerOnSharedPreferenceChangeListener(prefsChangedListener); 

in onCreate()