Change language programmatically (Android N 7.0 -

2019-03-10 11:48发布

问题:

I'm using the following code to set specific language in my app. Language is saved into SharedPreferences within the app. And it works perfectly up to API level 23. With Android N SharedPreferences works well too, it returns the correct language code-string, but it does not change the locale (sets default language of the phone). What could be wrong?

Update 1: When I use Log.v("MyLog", config.locale.toString()); immediately after res.updateConfiguration(config, dm) it returns correct locale, but language of the app does not changed.

Update 2: I also mentioned that if I change locale and then restart the activity (using new intent and finish on the old one), it changes the language properly, it even shows correct language after rotation. But when I close the app and open it again, I get default language. It's weird.

public class ActivityMain extends AppCompatActivity {

    //...
    @Override
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);
        // Set locale
        SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(this);
        String lang = pref.getString(ActivityMain.LANGUAGE_SAVED, "no_language");
        if (!lang.equals("no_language")) {
            Resources res = context.getResources();
            Locale locale = new Locale(lang);
            Locale.setDefault(locale);
            DisplayMetrics dm = res.getDisplayMetrics();
            Configuration config = res.getConfiguration();
            if (Build.VERSION.SDK_INT >= 17) {
                config.setLocale(locale);
            } else {
                config.locale = locale;
            }
        }
        res.updateConfiguration(config, dm);

        setContentView(R.layout.activity_main);
        //...
    } 
    //... 
}

Update 3: THE ANSWER IS ALSO HERE: https://stackoverflow.com/a/40849142/3935063

回答1:

Create a new class extends ContextWrapper

public class MyContextWrapper extends ContextWrapper {
    public MyContextWrapper(Context base) {
        super(base);
    }

    @TargetApi(Build.VERSION_CODES.N)
    public static ContextWrapper wrap(Context context, Locale newLocale) {
        Resources res = context.getResources();
        Configuration configuration = res.getConfiguration();

        if (VersionUtils.isAfter24()) {
            configuration.setLocale(newLocale);

            LocaleList localeList = new LocaleList(newLocale);
            LocaleList.setDefault(localeList);
            configuration.setLocales(localeList);

            context = context.createConfigurationContext(configuration);

        } else if (VersionUtils.isAfter17()) {
            configuration.setLocale(newLocale);
            context = context.createConfigurationContext(configuration);

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

        return new ContextWrapper(context);
    }
}

override Activity's attachBaseContext method

@Override
protected void attachBaseContext(Context newBase) {
    Locale languageType = LanguageUtil.getLanguageType(mContext);
    super.attachBaseContext(MyContextWrapper.wrap(newBase, languageType));
}

finish the activity and start it again,new locale will become effective.

demo:https://github.com/fanturbo/MultiLanguageDemo