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);

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);
}

androidx。Appcompat: Appcompat用户，以上解决方案将在1.3.0版本后工作。 就像这里提到的。

我知道现在回答有点晚了，但我在这里找到了这篇文章 ． 它很好地解释了整个过程，并为您提供了结构良好的代码。

Locale Helper类:

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 java.util.Locale;

/**
 * This class is used to change your application locale and persist this change for the next time
 * that your app is going to be used.
 * <p/>
 * You can also change the locale of your application on the fly by using the setLocale method.
 * <p/>
 * Created by gunhansancar on 07/10/15.
 */
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;
    }
}

您需要重写attachBaseContext并调用LocaleHelper.onAttach()来初始化应用程序中的语言环境设置。

import android.app.Application;
import android.content.Context;

import com.gunhansancar.changelanguageexample.helper.LocaleHelper;

public class MainApplication extends Application {
    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(LocaleHelper.onAttach(base, "en"));
    }
}

你所要做的就是相加

LocaleHelper.onCreate(this, "en");

只要你想改变locale。

对我来说，最好的解决办法是: https://www.bitcaal.com/how-to-change-the-app-language-programmatically-in-android/

package me.mehadih.multiplelanguage;

import androidx.appcompat.app.AppCompatActivity;

import android.content.res.Configuration;
import android.content.res.Resources;
import android.os.Build;
import android.os.Bundle;
import android.util.DisplayMetrics;

import java.util.Locale;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setApplicationLocale("az"); // short name of language. "en" for English
        setContentView(R.layout.activity_main);

    }

    private void setApplicationLocale(String locale) {
        Resources resources = getResources();
        DisplayMetrics dm = resources.getDisplayMetrics();
        Configuration config = resources.getConfiguration();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
            config.setLocale(new Locale(locale.toLowerCase()));
        } else {
            config.locale = new Locale(locale.toLowerCase());
        }
        resources.updateConfiguration(config, dm);
    }
}

Resources.updateConfiguration()已经弃用，我已经解决了这个问题，没有创建任何自定义的ContextWrapper。

首先我创建了一个扩展函数

fun Context.setAppLocale(language: String): Context {
    val locale = Locale(language)
    Locale.setDefault(locale)
    val config = resources.configuration
    config.setLocale(locale)
    config.setLayoutDirection(locale)
    return createConfigurationContext(config)
}

然后在活动的attachBaseContext方法中，简单地用新的上下文替换上下文。

override fun attachBaseContext(newBase: Context) {
  super.attachBaseContext(ContextWrapper(newBase.setAppLocale("bn")))
}