Android API 24 及更高版本中区域设置更改的 RTL 问题

Question

我试图在运行时更改应用程序的语言环境。它在 API 24 级以下的 Andorid 中工作正常。但是在 API 24 级或更高级别中，布局方向不会根据语言环境而改变。下面是在运行时更改语言环境的代码。我使用 LocaleHelper class 如下

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);
        Log.d("LocaleHelper", "language : "+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;
        configuration.setLayoutDirection(locale);
        resources.updateConfiguration(configuration, resources.getDisplayMetrics());

        return context;
    }
}

下面是我在 activity class

中使用的代码

public class MainActivity extends AppCompatActivity {
    @BindView(R.id.titleTextView)
    TextView mTitleTextView;
    @BindView(R.id.descTextView)
    TextView mDescTextView;
    @BindView(R.id.aboutTextView)
    TextView mAboutTextView;
    @BindView(R.id.toTRButton)
    Button mToTRButton;
    @BindView(R.id.toENButton)
    Button mToENButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

        setTitle(getString(R.string.main_activity_toolbar_title));
    }

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(LocaleHelper.onAttach(base));
    }

    @OnClick(R.id.toTRButton)
    public void onChangeToTRClicked() {
        updateViews("ur");
    }

    @OnClick(R.id.toENButton)
    public void onChangeToENClicked() {
        updateViews("en");
    }

    private void updateViews(String languageCode) {
        Context context = LocaleHelper.setLocale(this, languageCode);
        Resources resources = context.getResources();

        mTitleTextView.setText(resources.getString(R.string.main_activity_title));
        mDescTextView.setText(resources.getString(R.string.main_activity_desc));
        mAboutTextView.setText(resources.getString(R.string.main_activity_about));
        mToTRButton.setText(resources.getString(R.string.main_activity_to_tr_button));
        mToENButton.setText(resources.getString(R.string.main_activity_to_en_button));

        setTitle(resources.getString(R.string.main_activity_toolbar_title));
        this.recreate();
    }
}

并且在我的应用程序中 class 我添加了以下代码

@Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(LocaleHelper.onAttach(base, "en"));
    }

现在，当我将区域设置从英语更改为乌尔都语时，语言发生了变化，但布局方向并未按预期发生变化。当我再次单击乌尔都语时，布局方向发生变化（第二次尝试）。以下截图供参考

请帮忙解决问题

Answer 1

问题似乎是它没有反映第一次更新时布局方向的变化。我通过重写 Activity 的 onAttachedToWindow 方法解决了这个问题，如下所示：

@Override
public void onAttachedToWindow() {
    super.onAttachedToWindow();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        getWindow().getDecorView().setLayoutDirection(
                "ur".equals(LocaleHelper.getLanguage(this)) ?
                View.LAYOUT_DIRECTION_RTL : View.LAYOUT_DIRECTION_LTR);
    }
}

在 API 25 上测试过，运行良好。请小心，尽管我目前不确定这种方法是否有任何副作用。不过，我想这就是你要找的。

我还将更新 blog post 以反映更优雅、通用的代码。

Answer 2

package www.ourshopee.com.utils;

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.preference.PreferenceManager;
import android.support.annotation.RequiresApi;
import android.util.Log;

import java.util.Locale;

public class LocaleHelper {

    private static final String SELECTED_LANGUAGE = "Locale.Helper.Selected.Language";

    public static void onCreate(Context context) {
        String lang = getPersistedData(context, Locale.getDefault().getLanguage());
        setLocale(context, lang);
    }

    public static void onCreate(Context context, String defaultLanguage) {
        String lang = getPersistedData(context, defaultLanguage);
        setLocale(context, lang);
    }

    public static String getLanguage(Context context) {
        return getPersistedData(context, Locale.getDefault().getLanguage());
    }

    public static void setLocale(Context context, String language) {
        persist(context, language);


        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
             updateResources(context, language);
        }

           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();
    }



//    private static void updateResources(Context context, String language) {
//
//
//
//
//
//        Locale locale = new Locale(language);
//        Locale.setDefault(locale);
//        Configuration config = context.getResources().getConfiguration();
//        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
//            config.setLocale(locale);
//        }
//        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
//            context.createConfigurationContext(config);
//        }
//        context.getResources().updateConfiguration(config, context.getResources().getDisplayMetrics());
//
//
//
//
//
//
//    }







    @TargetApi(Build.VERSION_CODES.N)
    private static Context updateResources(Context context, String language) {
        Locale locale = new Locale(language);
        Log.d("LocaleHelper", "language above 24: "+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);
        Log.d("LocaleHelper", "language below 24: "+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;
    }

















}

Android API 24 及更高版本中区域设置更改的 RTL 问题

Android RTL issue in API 24 and higher on locale change

android

android-layout

localization

locale

android-7.0-nougat