创建一个类Extends Application并创建一个静态方法。 然后你可以在setContentView()之前的所有活动中调用这个方法。

public class MyApp extends Application {

@Override
public void onCreate() {
    super.onCreate();
}

public static void setLocaleFa (Context context){
    Locale locale = new Locale("fa"); 
    Locale.setDefault(locale);
    Configuration config = new Configuration();
    config.locale = locale;
    context.getApplicationContext().getResources().updateConfiguration(config, null);
}

public static void setLocaleEn (Context context){
    Locale locale = new Locale("en_US"); 
    Locale.setDefault(locale);
    Configuration config = new Configuration();
    config.locale = locale;
    context.getApplicationContext().getResources().updateConfiguration(config, null);
}

}

在活动中的使用:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    MyApp.setLocaleFa(MainActivity.this);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_main);
}

阿拉伯语/RTL支持

您必须通过- attachBaseContext()更新您的语言设置。 对于android版本N及以上，您必须使用createconfigationcontext () & updateConfiguration() -否则RTL布局无法正常工作

@Override protected void attachBaseContext(Context newBase) { super.attachBaseContext(updateBaseContextLocale(newBase)); } public Context updateBaseContextLocale(Context context) { String language = SharedPreference.getInstance().getValue(context, "lan");//it return "en", "ar" like this if (language == null || language.isEmpty()) { //when first time enter into app (get the device language and set it language = Locale.getDefault().getLanguage(); if (language.equals("ar")) { SharedPreference.getInstance().save(mContext, "lan", "ar"); } } Locale locale = new Locale(language); Locale.setDefault(locale); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { updateResourcesLocale(context, locale); return updateResourcesLocaleLegacy(context, locale); } return updateResourcesLocaleLegacy(context, locale); } @TargetApi(Build.VERSION_CODES.N) private Context updateResourcesLocale(Context context, Locale locale) { Configuration configuration = context.getResources().getConfiguration(); configuration.setLocale(locale); return context.createConfigurationContext(configuration); } @SuppressWarnings("deprecation") private Context updateResourcesLocaleLegacy(Context context, Locale locale) { Resources resources = context.getResources(); Configuration configuration = resources.getConfiguration(); configuration.locale = locale; resources.updateConfiguration(configuration, resources.getDisplayMetrics()); return context; }

唯一完全适合我的解决方案是结合Alex Volovoy的代码和应用程序重启机制:

void restartApplication() {
    Intent i = new Intent(MainTabActivity.context, MagicAppRestart.class);
    i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    MainTabActivity.context.startActivity(i);
}


/** This activity shows nothing; instead, it restarts the android process */
public class MagicAppRestart extends Activity {
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        finish();
    }

    protected void onResume() {
        super.onResume();
        startActivityForResult(new Intent(this, MainTabActivity.class), 0);         
    }
}

这段代码真的可以工作:

fa = 波斯语，en = 英语

注意:语言代码不能有“-”，必须是2个小写字母

在languageToLoad变量中输入您的语言代码:

import android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;

public class Main extends Activity {
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    String languageToLoad  = "fa"; // your language
    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);
  }
}

2021年6月更新(Kotlin):

class Main : Activity() {
    // Called when the activity is first created.
    public override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        
        val config = resources.configuration
        val lang = "fa" // your language code
        val locale = Locale(lang)
        Locale.setDefault(locale)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1)
            config.setLocale(locale)
        else
            config.locale = locale

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
            createConfigurationContext(config)
        resources.updateConfiguration(config, resources.displayMetrics)

        this.setContentView(R.layout.main)
    }
}

我改变了德语为我的应用程序开始自己。

这是我的正确密码。有人想用这个来代替我吗? (如何在android中编程改变语言)

我的代码:

Configuration config ; // variable declaration in globally

// this part is given inside onCreate Method starting and before setContentView()

public void onCreate(Bundle icic) 
{
    super.onCreate(icic);
    config = new Configuration(getResources().getConfiguration());
    config.locale = Locale.GERMAN ;
    getResources().updateConfiguration(config,getResources().getDisplayMetrics());

    setContentView(R.layout.newdesign);
}

这是工作时，我按下按钮改变我的TextView的文本语言。(strings.xml在值-de文件夹)

String languageToLoad = "de"; // your language
Configuration config = getBaseContext().getResources().getConfiguration();
Locale locale = new Locale(languageToLoad);
Locale.setDefault(locale);
config.locale = locale;
getBaseContext().getResources().updateConfiguration(config, getBaseContext().getResources().getDisplayMetrics());
recreate();