How to change Android O / Oreo / api 26 app language

Question

I want to change the language of the app and this works fine until API 26.

For api > 25 I put Locale.setDefault(Locale.Category.DISPLAY, mynewlanglocale); before setContentView(R.layout.activity_main); but nothing changes.

The docs don't explain too much about this.

Answer 1

I had the same problem: since Android 8.0+ some parts of my app did't change their language anymore. Updating of both application and activity context helps me. Here is an example of MainActivity function:

private void setApplicationLanguage(String newLanguage) {
    Resources activityRes = getResources();
    Configuration activityConf = activityRes.getConfiguration();
    Locale newLocale = new Locale(newLanguage);
    activityConf.setLocale(newLocale);
    activityRes.updateConfiguration(activityConf, activityRes.getDisplayMetrics());

    Resources applicationRes = getApplicationContext().getResources();
    Configuration applicationConf = applicationRes.getConfiguration();
    applicationConf.setLocale(newLocale);
    applicationRes.updateConfiguration(applicationConf, 
    applicationRes.getDisplayMetrics());
}

Answer 2

Yes in android Oreo localization is not working fine with updateconfiguration. But it is deprecated in android N itself. Instead of updateconfiguration use createconfiguration in each attachcontext. it is working fine for me. Try this...

In you activity add this..

@Override
protected void attachBaseContext(Context newBase) {
    if(Build.VERSION.SDK_INT > Build.VERSION_CODES.N_MR1) {
        super.attachBaseContext(MyContextWrapper.wrap(newBase, "ta"));
    }
    else {
        super.attachBaseContext(newBase);
    }
}

In MyContextWrapper.java

 public static ContextWrapper wrap(Context context, String language) {
    Resources res = context.getResources();
    Configuration configuration = res.getConfiguration();
    Locale newLocale = new Locale(language);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        configuration.setLocale(newLocale);
        LocaleList localeList = new LocaleList(newLocale);
        LocaleList.setDefault(localeList);
        configuration.setLocales(localeList);
        context = context.createConfigurationContext(configuration);

    } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        configuration.setLocale(newLocale);
        context = context.createConfigurationContext(configuration);

    } else {
        configuration.locale = newLocale;
        res.updateConfiguration(configuration, res.getDisplayMetrics());
    }

    return new ContextWrapper(context);
}

Answer 3

updateConfiguration is deprecated and you should use createConfigurationContext. I solved it this way:

    @Override
    protected void attachBaseContext(Context newBase) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            Configuration config = newBase.getResources().getConfiguration();
            //Update your config with the Locale i. e. saved in SharedPreferences
            SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(newBase);
            String language = prefs.getString(SP_KEY_LANGUAGE, "en_US");
            Locale.setDefault(locale);
            config.setLocale(new Locale(language));
            newBase = newBase.createConfigurationContext(config);
        }
        super.attachBaseContext(newBase);
    }