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);

首先为不同的语言创建多个string.xml;然后在onCreate()方法中使用这段代码:

super.onCreate(savedInstanceState);
String languageToLoad  = "fr"; // change your language here
Locale locale = new Locale(languageToLoad); 
Locale.setDefault(locale);
Configuration config = new Configuration();
config.locale = locale;
getBaseContext().getResources().updateConfiguration(config, 
  getBaseContext().getResources().getDisplayMetrics());
this.setContentView(R.layout.main);

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; } }

这里列出的解决方案没有一个对我有用。

如果AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)，语言没有在android >= 7.0上切换

这个LocaleUtils工作得很好: https://gist.github.com/GigigoGreenLabs/7d555c762ba2d3a810fe

LocaleUtils

public class LocaleUtils {

public static final String LAN_SPANISH      = "es";
public static final String LAN_PORTUGUESE   = "pt";
public static final String LAN_ENGLISH      = "en";

private static Locale sLocale;

public static void setLocale(Locale locale) {
    sLocale = locale;
    if(sLocale != null) {
        Locale.setDefault(sLocale);
    }
}

public static void updateConfig(ContextThemeWrapper wrapper) {
    if(sLocale != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        Configuration configuration = new Configuration();
        configuration.setLocale(sLocale);
        wrapper.applyOverrideConfiguration(configuration);
    }
}

public static void updateConfig(Application app, Configuration configuration) {
    if(sLocale != null && Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
        //Wrapping the configuration to avoid Activity endless loop
        Configuration config = new Configuration(configuration);
        config.locale = sLocale;
        Resources res = app.getBaseContext().getResources();
        res.updateConfiguration(config, res.getDisplayMetrics());
    }
}
}

将此代码添加到应用程序

public class App extends Application {
public void onCreate(){
    super.onCreate();

    LocaleUtils.setLocale(new Locale("iw"));
    LocaleUtils.updateConfig(this, getBaseContext().getResources().getConfiguration());
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    LocaleUtils.updateConfig(this, newConfig);
}
}

活动中的代码

public class BaseActivity extends AppCompatActivity {
    public BaseActivity() {
        LocaleUtils.updateConfig(this);
    }
}

这是有可能的。您可以设置区域。然而，我不建议这样做。我们在早期阶段尝试过，基本上是在对抗这个系统。

我们对改变语言有同样的要求，但决定接受UI应该与手机UI相同的事实。它是通过设置locale工作，但太bug了。根据我的经验，每次输入活动(每个活动)时都必须设置它。这里是一个代码，如果你仍然需要这个(再次强调，我不推荐)

Resources res = context.getResources();
// Change locale settings in the app.
DisplayMetrics dm = res.getDisplayMetrics();
android.content.res.Configuration conf = res.getConfiguration();
conf.setLocale(new Locale(language_code.toLowerCase())); // API 17+ only.
// Use conf.locale = new Locale(...) if targeting lower versions
res.updateConfiguration(conf, dm);

如果您有特定于语言的内容-您可以根据设置更改它。

2020年3月26日更新

    public static 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());
    }

注意:语言代码不能有“-”，必须是2个小写字母

Locale locale = new Locale("en");
Locale.setDefault(locale);

Configuration config = context.getResources().getConfiguration();
config.setLocale(locale);
context.createConfigurationContext(config);

重要更新:

context.getResources().updateConfiguration(config, context.getResources().getDisplayMetrics());

注意，在SDK >= 21上，你需要调用' resources . updateconfiguration()'，否则资源将不会被更新。