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);

Answer 1

Here is complete solution worked for kitkat, Lollipop, Marshmallow, Nougat and Oreo too. Just follow all below step.

First create a java class like below

import android.content.Context;
import android.content.res.Configuration;
import java.util.Locale;
public class LocaleUtils {
public static void updateConfig(Context mContext, String sLocale) {
    Locale locale = new Locale(sLocale);
    Locale.setDefault(locale);
    Configuration config = mContext.getResources().getConfiguration();
    config.locale = locale;
    mContext.getResources().updateConfiguration(config,
            mContext.getResources().getDisplayMetrics());
  }
}

Now add this snippet on Button click where you want to change locale

String lang="hi";//pass your language here
SharedPreferences preferences =  PreferenceManager.getDefaultSharedPreferences(mContext);
                        SharedPreferences.Editor editor = preferences.edit();
                        editor.clear();
                        editor.putString("lang", lang");
                        editor.putBoolean("langSelected", true);
                        editor.apply();
                        LocaleUtils.updateConfig(mContext,lang);
                        Intent intent = mContext.getIntent();
                        mContext.overridePendingTransition(0, 0);
                        mContext.finish();
                        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
                        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                        mContext.overridePendingTransition(0, 0);
                        mContext.startActivity(intent);

Finally paste the below code in Splash Activity or in Launching Activity.

SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
    String lang = preferences.getString("lang", "");
    boolean langSelected = preferences.getBoolean("langSelected", false);
    SharedPreferences.Editor editor = preferences.edit();
    if (langSelected) {
        editor.clear();
        editor.putString("lang", lang);
        editor.putBoolean("langSelected", true);
        editor.apply();
        LocaleUtils.updateConfig(this,lang);
    } else {
        LocaleUtils.updateConfig(this, Locale.getDefault().getLanguage());
        editor.clear();
        editor.putString("lang", Locale.getDefault().getLanguage());
        editor.putBoolean("langSelected", false);
        editor.apply();
    }