Android Preferences: How to load the default values when the user hasn"t used the preferences-screen?
I am using a PreferenceActivity to let the user set some values. I am feeding it the xml file with the defined preferences.
I have set all the android:defaultValue="" for them.
When I start my application, I need the preferences, or if they are not set yet manually, I want the default values:
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
boolean value = prefs.getBoolean("key"), false);
However, when android:defaultValue="true" I still get false . So, it looks like the defaultValues set in the XML are not used anywhere but when initializing the preferences-screen.
I don't want to hardcode the default values in the getBoolean() method. So, is there a way get the default-values with only defining these in 1 place?
this question is similar to mine:
ReplyDeleteinitialize-preferences-from-xml-in-main-activity
Just use this code in onCreate method:
PreferenceManager.setDefaultValues(this, R.xml.preference, false);
It will load your preferences from XML, and last parameter (readAgain) will guarantee that user preferences won't be overwritten.
Take a look into PreferenceManager.setDefaultValues in Android API for further investigation.
Be aware that if you are using getSharedPreferences(String sharedPreferencesName, int sharedPreferencesMode) to retrieve preferences you have to use PreferenceManager.setDefaultValues(Context context, String sharedPreferencesName, int sharedPreferencesMode, int resId, boolean readAgain) to set defaults! For example:
ReplyDeletePreferenceManager.setDefaultValues(this, PREFS_NAME, Context.MODE_PRIVATE, R.xml.preference, false);
I hope this can help someone.
For example extending DialogPreference I do this:
ReplyDelete@Override
protected void onSetInitialValue(boolean restore, Object defaultValue) {
super.onSetInitialValue(restore, defaultValue);
if (restore) {
mValue = shouldPersist() ? getPersistedString(mDefault) : mDefault;
} else {
mValue = mDefault;
}
}
mDefault can be:
mContext.getResources().getString(attrs.getAttributeResourceValue(androidns,"defaultValue", 100));
something you have indexed in R.