CODEWITHSUNDEEP
androidsharedpreferences
Al Lelopath
Al Lelopath

Reputation: 6778

Accessing SharedPreferences

I have a problem in the LiveWallpaper app (my first) I am developing. Consider 2 classes: LiveWallpaperService and LiveWallpaperSettings. LiveWallpaperSettings extends PreferencyActivity. Example data representing the preferences selected by the user, for example a boolean displaySprite (true=> display the sprite on the screen, false do not display) are saved/persisted via SharedPreferences in LiveWallpaperSettings.

Upon starting the application (Settings -> Display -> LiveWallpaper -> MyLiveWallpaper), the saved preferences need to be known so that the sprite can be displayed or not. However, LiveWallpaperSettings is not instantiated until the Settings button is clicked, so SharedPreferences is not available, and thus saved settings are unavailable until then.

I tried this in LiveWallpaperService.onCreateScene(), but it has no data in it:
SharedPreferences startupPrefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());

What can I do?

Upvotes: 0

Views: 166

Answers (2)

Hoan Nguyen
Hoan Nguyen

Reputation: 18151

In your preferences xml set the default value and in your MainActivity onCreate() add the following code setDefaultValues(this, R.xml.yourxmlname, false);

Upvotes: 0

Oli
Oli

Reputation: 3546

There is a default value if the entry/sharedpref file does not exist:

SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(this);
boolean display = settings.getBoolean("display", true);

"public abstract boolean getBoolean (String key, boolean defValue)"

Added in API level 1 Retrieve a boolean value from the preferences.

Parameters key The name of the preference to retrieve. defValue Value to return if this preference does not exist.

Hope I didnt misunderstood your question :)

Upvotes: 1

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