Unable to change language in Oreo

问题

I'm trying to use Arabic and English in my app. Its working fine on devices running on android Nougat or below. But it's not working on oreo devices. Is there some new code requirement in API 26? I am using the code below.

public void changeLanguage(Context context, String language) {
    Locale locale = new Locale(language);
    Locale.setDefault(locale);
    Configuration config = context.getResources().getConfiguration();
    config.setLocale(locale);
    context.createConfigurationContext(config);
    context.getResources().updateConfiguration(config, context.getResources().getDisplayMetrics());
}

and I'm passing "en" and "ar" as language argument.

回答1:

When you set new Locale you should restart your Activity. You can perform it using the next snippet of code:

private void restartActivity() {
    Intent intent = getIntent();
    finish();
    startActivity(intent);
}

Then your changeLanguage() method will look in a next way:

public void changeLanguage(Context context, String language) {
    Locale locale = new Locale(language);
    Locale.setDefault(locale);
    Configuration config = context.getResources().getConfiguration();
    config.setLocale(locale);
    context.createConfigurationContext(config);
    context.getResources().updateConfiguration(config, context.getResources().getDisplayMetrics());

    restartActivity();
}

回答2:

I recently faced issue related to layout direction on Oreo. Resources were being updated but Layout direction not changing.

Below code worked for me.

 public static void setRTLSupportIfRequired(AppCompatActivity activity) {
        if(getLanguageFromPrefs(activity).equals("ar")) {
            activity.getWindow().getDecorView().setLayoutDirection(View.LAYOUT_DIRECTION_RTL);
        }else{
            activity.getWindow().getDecorView().setLayoutDirection(View.LAYOUT_DIRECTION_LTR);
        }

    }

Note: Previously I were using View.LAYOUT_DIRECTION_LOCALE but it was not working on Oreo

回答3:

Locale locale = new Locale(lang);
    Locale.setDefault(locale);
    Configuration config = new Configuration();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        config.setLocale(locale);
    } else {
        config.locale = locale;
    }
    context.getApplicationContext().getResources().updateConfiguration(config,
            context.getApplicationContext().getResources().getDisplayMetrics());

This worked for me.

回答4:

I had same problem before and after some research I find out one solution. Create custom language aware context wrapper and attach on your activity's attachBaseContext() method.

@SuppressWarnings("NewApi")
public static LanguageAwareContext newLanguageAwareContext(String targetLanguage, Context context) {
    Resources resources = context.getResources();
    Configuration configuration = resources.getConfiguration();

    Locale newLocale = new Locale(targetLanguage);

    if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N) {
        configuration.setLocale(newLocale);
        LocaleList.setDefault(new LocaleList(newLocale));

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

    return new LanguageAwareContext(context);
}

override attachBaseContext method and change with your customized context wrapper

@Override
protected void attachBaseContext(Context newBase) {
    newBase = LanguageAwareContext.newLanguageAwareContext("en",newBase);

    super.attachBaseContext(newBase);
}

回答5:

Yes, there is issue with Android Oreo for language change(strings and layout direction in arabic,urdu and hebrew), i found the solution this will help you to solve this problem

In LanguageContextWrapper.java class

 public static ContextWrapper wrap(Context context, String language) {
            Locale locale = new Locale(language);
            Locale.setDefault(locale);
            Resources resources = context.getResources();
            Configuration configuration = resources.getConfiguration();
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                configuration.setLocale(locale);
                LocaleList localeList = new LocaleList(locale);
                LocaleList.setDefault(localeList);
                configuration.setLocales(localeList);
                configuration.setLayoutDirection(locale);
                context.createConfigurationContext(configuration);
            } else {
                configuration.locale = locale;
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
                    configuration.setLayoutDirection(locale);
                }
            }
            resources.updateConfiguration(configuration, resources.getDisplayMetrics());

        return new LanguageContextWrapper(context);
    }

In activity class override following method

 override fun attachBaseContext(base: Context) {
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N_MR1) {
            super.attachBaseContext(LanguageContextWrapper.wrap(base, Locale.getDefault().language))
        } else {
            super.attachBaseContext(base)
        }
    }

And after change language we have to recreate activity, we need to write following code

fun recreateActivity(){
    if (Build.VERSION.SDK_INT in 26..27) {
                    if (Locale.getDefault().language == "ar" ||
                            Locale.getDefault().language == "iw" ||
                            Locale.getDefault().language == "ur")
                        window.decorView.layoutDirection = View.LAYOUT_DIRECTION_RTL
                    else
                        window.decorView.layoutDirection = View.LAYOUT_DIRECTION_LTR
                }
                recreate()

  }

来源：https://stackoverflow.com/questions/47978265/unable-to-change-language-in-oreo