Android实现应用内置语言切换功能

<resources>   <string name="app_name">SwitchLanguage</string>   <string name="helloworld">Hello World!</string>   <string name="language">Eng</string>   <string name="english">English</string>   <string name="chinese">中文</string>   <string name="russian">русский</string>   <string name="secondact">Second Activity</string> </resources> 

<resources>   <string name="app_name">Переключение язык</string>   <string name="helloworld">привет мир!</string>   <string name="language">русский</string>   <string name="secondact">второй активность</string> </resources> 

<resources>   <string name="app_name">切换语言</string>   <string name="helloworld">你好 世界!</string>   <string name="language">中文</string>   <string name="secondact">第二屏</string> </resources> 

<?xml version="1.0" encoding="utf-8"?> <LinearLayout   android:id="@+id/activity_main"   xmlns:android="http://schemas.android.com/apk/res/android"   xmlns:tools="http://schemas.android.com/tools"   android:layout_width="match_parent"   android:layout_height="match_parent"   android:orientation="vertical"   tools:context="com.ce.switchlanguage.MainActivity"   xmlns:app="http://schemas.android.com/apk/res-auto">   <android.support.design.widget.AppBarLayout     android:layout_height="wrap_content"     android:layout_width="match_parent"     android:theme="@style/AppTheme.AppBarOverlay">      <android.support.v7.widget.Toolbar       android:id="@+id/toolbar"       android:layout_width="match_parent"       android:layout_height="?attr/actionBarSize"       android:background="?attr/colorPrimary"       app:popupTheme="@style/AppTheme.PopupOverlay"       app:title="@string/app_name"/>    </android.support.design.widget.AppBarLayout>   <TextView     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:text="@string/helloworld"/>   <Button     android:id="@+id/change"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_gravity="center"     android:text="@string/language"/> </LinearLayout> 

<resources>   <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">     <item name="colorPrimary">@color/colorPrimary</item>     <item name="colorPrimaryDark">@color/colorPrimaryDark</item>     <item name="colorAccent">@color/colorAccent</item>     <item name="windowActionBar">false</item>     <item name="windowNoTitle">true</item>     <item name="android:windowDisablePreview">true</item>   </style>   <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar"/>   <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Dark"/> </resources> 

<?xml version="1.0" encoding="utf-8"?> <menu xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto">   <item android:id="@+id/chinese" android:title="@string/chinese" app:showAsAction="never" />   <item android:id="@+id/english" android:title="@string/english" app:showAsAction="never" />   <item android:id="@+id/russian" android:title="@string/russian" app:showAsAction="never" /> </menu> 

package com.ce.switchlanguage;  import android.content.Context; import android.content.SharedPreferences; import android.content.res.Configuration; import android.os.Build; import android.util.DisplayMetrics;  import com.google.gson.Gson;  import java.util.Locale;  public class LocaleUtils {   /**    * 中文    */   public static final Locale LOCALE_CHINESE = Locale.CHINESE;   /**    * 英文    */   public static final Locale LOCALE_ENGLISH = Locale.ENGLISH;   /**    * 俄文    */   public static final Locale LOCALE_RUSSIAN = new Locale("ru");   /**    * 保存SharedPreferences的文件名    */   private static final String LOCALE_FILE = "LOCALE_FILE";   /**    * 保存Locale的key    */   private static final String LOCALE_KEY = "LOCALE_KEY";    /**    * 获取用户设置的Locale    * @param pContext Context    * @return Locale    */   public static Locale getUserLocale(Context pContext) {     SharedPreferences _SpLocale = pContext.getSharedPreferences(LOCALE_FILE, Context.MODE_PRIVATE);     String _LocaleJson = _SpLocale.getString(LOCALE_KEY, "");     return jsonToLocale(_LocaleJson);   }   /**    * 获取当前的Locale    * @param pContext Context    * @return Locale    */   public static Locale getCurrentLocale(Context pContext) {     Locale _Locale;     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { //7.0有多语言设置获取顶部的语言       _Locale = pContext.getResources().getConfiguration().getLocales().get(0);     } else {       _Locale = pContext.getResources().getConfiguration().locale;     }     return _Locale;   }   /**    * 保存用户设置的Locale    * @param pContext Context    * @param pUserLocale Locale    */   public static void saveUserLocale(Context pContext, Locale pUserLocale) {     SharedPreferences _SpLocal=pContext.getSharedPreferences(LOCALE_FILE, Context.MODE_PRIVATE);     SharedPreferences.Editor _Edit=_SpLocal.edit();     String _LocaleJson = localeToJson(pUserLocale);     _Edit.putString(LOCALE_KEY, _LocaleJson);     _Edit.apply();   }   /**    * Locale转成json    * @param pUserLocale UserLocale    * @return json String    */   private static String localeToJson(Locale pUserLocale) {     Gson _Gson = new Gson();     return _Gson.toJson(pUserLocale);   }   /**    * json转成Locale    * @param pLocaleJson LocaleJson    * @return Locale    */   private static Locale jsonToLocale(String pLocaleJson) {     Gson _Gson = new Gson();     return _Gson.fromJson(pLocaleJson, Locale.class);   }   /**    * 更新Locale    * @param pContext Context    * @param pNewUserLocale New User Locale    */   public static void updateLocale(Context pContext, Locale pNewUserLocale) {     if (needUpdateLocale(pContext, pNewUserLocale)) {       Configuration _Configuration = pContext.getResources().getConfiguration();       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {         _Configuration.setLocale(pNewUserLocale);       } else {         _Configuration.locale =pNewUserLocale;       }       DisplayMetrics _DisplayMetrics = pContext.getResources().getDisplayMetrics();       pContext.getResources().updateConfiguration(_Configuration, _DisplayMetrics);       saveUserLocale(pContext, pNewUserLocale);     }   }   /**    * 判断需不需要更新    * @param pContext Context    * @param pNewUserLocale New User Locale    * @return true / false    */   public static boolean needUpdateLocale(Context pContext, Locale pNewUserLocale) {     return pNewUserLocale != null && !getCurrentLocale(pContext).equals(pNewUserLocale);   } } 

package com.ce.switchlanguage;  import android.content.Intent; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.Menu; import android.view.MenuItem;  public class MainActivity extends AppCompatActivity {    @Override   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     Toolbar _Toolbar =(Toolbar) findViewById(R.id.toolbar);     setSupportActionBar(_Toolbar);   }    @Override   public boolean onCreateOptionsMenu(Menu menu) {     getMenuInflater().inflate(R.menu.main_menu,menu);     return true;   }    @Override   public boolean onOptionsItemSelected(MenuItem item) {     int _ItemId=item.getItemId();     switch (_ItemId) {       case R.id.chinese:         if (LocaleUtils.needUpdateLocale(this, LocaleUtils.LOCALE_CHINESE)) {           LocaleUtils.updateLocale(this, LocaleUtils.LOCALE_CHINESE);           restartAct();         }         break;       case R.id.english:         if (LocaleUtils.needUpdateLocale(this, LocaleUtils.LOCALE_ENGLISH)) {           LocaleUtils.updateLocale(this, LocaleUtils.LOCALE_ENGLISH);           restartAct();         }         break;       case R.id.russian:         if (LocaleUtils.needUpdateLocale(this, LocaleUtils.LOCALE_RUSSIAN)) {           LocaleUtils.updateLocale(this, LocaleUtils.LOCALE_RUSSIAN);           restartAct();         }     }     return true;   }    /**    * 重启当前Activity    */   private void restartAct() {     finish();     Intent _Intent = new Intent(this, MainActivity.class);     startActivity(_Intent);     //清除Activity退出和进入的动画     overridePendingTransition(0, 0);   } } 

package com.ce.switchlanguage;  import android.app.Application; import android.content.res.Configuration; import android.os.Build;  import java.util.Locale;  public class MyApplication extends Application {   @Override   public void onCreate() {     super.onCreate();     Locale _UserLocale=LocaleUtils.getUserLocale(this);     LocaleUtils.updateLocale(this, _UserLocale);   }    @Override   public void onConfigurationChanged(Configuration newConfig) {     super.onConfigurationChanged(newConfig);     Locale _UserLocale=LocaleUtils.getUserLocale(this);     //系统语言改变了应用保持之前设置的语言     if (_UserLocale != null) {       Locale.setDefault(_UserLocale);       Configuration _Configuration = new Configuration(newConfig);       if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {         _Configuration.setLocale(_UserLocale);       } else {         _Configuration.locale =_UserLocale;       }       getResources().updateConfiguration(_Configuration, getResources().getDisplayMetrics());     }   } }