我终于弄清楚如何设置它工作在两个=N安卓版本。

用你自己的抽象类扩展AppCompatActivity，比如:

abstract class MLAppCompatActivity : AppCompatActivity() {
  override fun attachBaseContext(newBase: Context?) {
    super.attachBaseContext(LocaleHelper.wrap(newBase))
  }

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
        LocaleHelper.wrap(this)
    }
  }
}

attachBaseContext在Android >=N版本上被调用，这样activity将使用正确的上下文。在Android <N上，我们必须以另一种方式调用这个函数，在设置内容视图之前。因此，我们重写onCreate函数来设置正确的上下文。 意思是，每当你创建一个新的Activity时，你必须扩展你的抽象类。比如这个:

class TermsActivity : MLAppCompatActivity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_terms)
  }
}

最后LocaleHelper是这样的:

import android.annotation.TargetApi;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.util.DisplayMetrics;

import com.at_zone.constants.SharedPreferencesKeys;

import java.util.Locale;

public class LocaleHelper extends ContextWrapper {

    public LocaleHelper(Context base) {
        super(base);
    }

    public static Context wrap(Context context) {
        SharedPreferences sharedPreferences = context.getSharedPreferences(
                SharedPreferencesKeys.SHARED_PREFERENCES, Context.MODE_PRIVATE
        );
        String language = sharedPreferences.getString(SharedPreferencesKeys.CURRENT_LANGUAGE, "default");
        if (!language.equals("default")) {
            Configuration config = context.getResources().getConfiguration();
            if (!language.equals("")) {
                Locale locale = new Locale(language);
                Locale.setDefault(locale);
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                    setSystemLocale(config, locale);
                } else {
                    setSystemLocaleLegacy(context, config, locale);
                }
                config.setLayoutDirection(locale);
                context = context.createConfigurationContext(config);
            }
            return new LocaleHelper(context);
        }
        return context;
    }

    public static String getSystemLanguage(Context context) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            return getSystemLocale(context).getLanguage().toLowerCase();
        } else {
            return getSystemLocaleLegacy(context).getLanguage().toLowerCase();
        }
    }

    public static Locale getSystemLocaleLegacy(Context context) {
        Configuration config = context.getResources().getConfiguration();
        return config.locale;
    }

    @TargetApi(Build.VERSION_CODES.N)
    public static Locale getSystemLocale(Context context) {
        return context.getResources().getConfiguration().getLocales().get(0);
    }

    public static void setSystemLocaleLegacy(Context context, Configuration config, Locale locale) {
        config.locale = locale;
        Resources res = context.getResources();
        DisplayMetrics dm = res.getDisplayMetrics();
        res.updateConfiguration(config, dm);
    }

    @TargetApi(Build.VERSION_CODES.N)
    public static void setSystemLocale(Configuration config, Locale locale) {
        config.setLocale(locale);
    }

}

/*change language at Run-time*/
//use method like that:
//setLocale("en");
 public void setLocale(String lang) { 
  myLocale = new Locale(lang);         
  Resources res = getResources();         
  DisplayMetrics dm = res.getDisplayMetrics();         
  Configuration conf = res.getConfiguration();         
  conf.locale = myLocale;         
  res.updateConfiguration(conf, dm);         
  Intent refresh = new Intent(this, AndroidLocalize.class);         
  startActivity(refresh); 
 }

您可以要求用户在第一个屏幕中选择语言并将其保存在SharedPreferences中

SharedPreferences.Editor editor = getSharedPreferences("data", MODE_PRIVATE).edit();
editor.putString("lang", "si");
editor.apply();
    
recreate();

然后你可以在应用程序中的每个Activity中使用它。这里我设置了英语和僧伽罗语。

@Override
protected void attachBaseContext(Context base) {
    SharedPreferences prefs = base.getSharedPreferences("uinfo", MODE_PRIVATE);
    String restoredText = prefs.getString("lang", "No name defined");

    if (restoredText.equals("si")){
        super.attachBaseContext(LocaleHelper.localeUpdateResources(base, "si"));
    }else{
        super.attachBaseContext(LocaleHelper.localeUpdateResources(base, "en"));
    }
}

这是你的localUpdateResources方法。把它放在LocalHelper类中

public class LocaleHelper {
    public static Context localeUpdateResources(Context context, String languageCode) {

        Context newContext = context;

        Locale locale = new Locale(languageCode);
        Locale.setDefault(locale);

        Resources resources = context.getResources();
        Configuration config = new Configuration(resources.getConfiguration());

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {

            config.setLocale(locale);
            newContext = context.createConfigurationContext(config);

        } else {

            config.locale = locale;
            resources.updateConfiguration(config, resources.getDisplayMetrics());
        }

        return newContext;

    }
}

如果你正在使用片段，并且你想在Android中以编程方式更改应用程序语言，请使用此方法

  public void setLocale(Activity activity, String languageCode) {
    Locale locale = new Locale(languageCode);
    Locale.setDefault(locale);
    Resources resources = activity.getResources();
    Configuration config = resources.getConfiguration();
    config.setLocale(locale);
    resources.updateConfiguration(config, resources.getDisplayMetrics());
     SettingsFragment settingsFragment = new SettingsFragment();
     FragmentManager fragmentManager = requireActivity().getSupportFragmentManager();
     FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    activity.overridePendingTransition(0,0);
     fragmentTransaction.replace(R.id.main, settingsFragment).commit();
}

这样叫它

setLocale(requireActivity(),"fr");

只需要用你的片段名改变SettingsFragment，在你调用方法的地方，这基本上是刷新布局来获得视图上的新字符串 如果你想在另一个类上设置这个方法只需像这样添加context

public void setLocale(Activity activity, String languageCode,Context context) {
    Locale locale = new Locale(languageCode);
    Locale.setDefault(locale);
    Resources resources = activity.getResources();
    Configuration config = resources.getConfiguration();
    config.setLocale(locale);
    resources.updateConfiguration(config, resources.getDisplayMetrics());
    SettingsFragment settingsFragment = new SettingsFragment();
    FragmentManager fragmentManager = ((AppCompatActivity) context).getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    activity.overridePendingTransition(0,0);
    fragmentTransaction.replace(R.id.main, settingsFragment).commit();
}

我正在寻找一种以编程方式改变系统语言的方法。 虽然我完全理解一个正常的应用程序不应该这样做，而是:

用户应该(通过一个意图)指向系统设置手动更改它 应用程序应该自己处理本地化，就像Alex的回答中描述的那样

有必要从程序上真正改变系统的语言。

这是没有文档的API，因此不应该用于市场/最终用户应用程序!

不管怎样，这是我找到的解决方案:

  Locale locale = new Locale(targetLocaleAsString);

  Class amnClass = Class.forName("android.app.ActivityManagerNative");
  Object amn = null;
  Configuration config = null;

  // amn = ActivityManagerNative.getDefault();
  Method methodGetDefault = amnClass.getMethod("getDefault");
  methodGetDefault.setAccessible(true);
  amn = methodGetDefault.invoke(amnClass);

  // config = amn.getConfiguration();
  Method methodGetConfiguration = amnClass.getMethod("getConfiguration");
  methodGetConfiguration.setAccessible(true);
  config = (Configuration) methodGetConfiguration.invoke(amn);

  // config.userSetLocale = true;
  Class configClass = config.getClass();
  Field f = configClass.getField("userSetLocale");
  f.setBoolean(config, true);

  // set the locale to the new value
  config.locale = locale;

  // amn.updateConfiguration(config);
  Method methodUpdateConfiguration = amnClass.getMethod("updateConfiguration", Configuration.class);
  methodUpdateConfiguration.setAccessible(true);
  methodUpdateConfiguration.invoke(amn, config);

根据这篇文章。您需要下载那篇文章中引用的LocaleHelper.java。

Create MyApplication class that will extends Application Override attachBaseContext() to update language. Register this class in manifest. public class MyApplication extends Application { @Override protected void attachBaseContext(Context base) { super.attachBaseContext(LocaleHelper.onAttach(base, "en")); } } <application android:name="com.package.MyApplication" .../> Create BaseActivity and override onAttach() to update language. Needed for Android 6+ public class BaseActivity extends Activity { @Override protected void attachBaseContext(Context base) { super.attachBaseContext(LocaleHelper.onAttach(base)); } } Make all activities on your app extends from BaseActivity. public class LocaleHelper { private static final String SELECTED_LANGUAGE = "Locale.Helper.Selected.Language"; public static Context onAttach(Context context) { String lang = getPersistedData(context, Locale.getDefault().getLanguage()); return setLocale(context, lang); } public static Context onAttach(Context context, String defaultLanguage) { String lang = getPersistedData(context, defaultLanguage); return setLocale(context, lang); } public static String getLanguage(Context context) { return getPersistedData(context, Locale.getDefault().getLanguage()); } public static Context setLocale(Context context, String language) { persist(context, language); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { return updateResources(context, language); } return updateResourcesLegacy(context, language); } private static String getPersistedData(Context context, String defaultLanguage) { SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context); return preferences.getString(SELECTED_LANGUAGE, defaultLanguage); } private static void persist(Context context, String language) { SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context); SharedPreferences.Editor editor = preferences.edit(); editor.putString(SELECTED_LANGUAGE, language); editor.apply(); } @TargetApi(Build.VERSION_CODES.N) private static Context updateResources(Context context, String language) { Locale locale = new Locale(language); Locale.setDefault(locale); Configuration configuration = context.getResources().getConfiguration(); configuration.setLocale(locale); configuration.setLayoutDirection(locale); return context.createConfigurationContext(configuration); } @SuppressWarnings("deprecation") private static Context updateResourcesLegacy(Context context, String language) { Locale locale = new Locale(language); Locale.setDefault(locale); Resources resources = context.getResources(); Configuration configuration = resources.getConfiguration(); configuration.locale = locale; if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) { configuration.setLayoutDirection(locale); } resources.updateConfiguration(configuration, resources.getDisplayMetrics()); return context; } }