update

packages/frontend/src/i18n.ts

@@ -7,20 +7,26 @@ import zhMessages from './locales/zh.json';
 // 类型推断 (可选，但推荐)
 type MessageSchema = typeof enMessages; // 假设 en.json 包含所有 key
 
-// 获取浏览器语言或默认语言
-const getInitialLocale = (): string => {
-  const navigatorLang = navigator.language?.split('-')[0]; // 获取 'en', 'zh' 等
-  if (navigatorLang === 'zh') {
-    return 'zh';
+// 定义默认语言
+export const defaultLng = 'en';
+const localStorageKey = 'user-locale';
+
+// 尝试从 localStorage 获取语言，否则回退
+const getInitialLocaleFromStorage = (): 'en' | 'zh' => {
+  const storedLocale = localStorage.getItem(localStorageKey);
+  if (storedLocale === 'en' || storedLocale === 'zh') {
+    return storedLocale;
   }
-  // 可以添加更多语言支持
-  return 'en'; // 默认英文
+  // Fallback logic (e.g., browser language or default)
+  const navigatorLang = navigator.language?.split('-')[0];
+  return navigatorLang === 'zh' ? 'zh' : defaultLng;
 };
 
+
 const i18n = createI18n<[MessageSchema], 'en' | 'zh'>({
   legacy: false, // 必须设置为 false 才能在 Composition API 中使用 useI18n
-  locale: getInitialLocale(), // 设置初始语言
-  fallbackLocale: 'en', // 如果当前语言缺少某个 key，则回退到英文
+  locale: getInitialLocaleFromStorage(), // 使用从 localStorage 或回退获取的初始语言
+  fallbackLocale: defaultLng, // 如果当前语言缺少某个 key，则回退到默认语言
   messages: {
     en: enMessages,
     zh: zhMessages,
@@ -30,4 +36,23 @@ const i18n = createI18n<[MessageSchema], 'en' | 'zh'>({
   // silentFallbackWarn: true,
 });
 
+/**
+ * 设置 i18n 实例的区域设置
+ * @param lang 要设置的语言代码 ('en', 'zh', etc.)
+ */
+export const setLocale = (lang: 'en' | 'zh') => {
+  if (i18n.global.availableLocales.includes(lang)) {
+    i18n.global.locale = lang; // 直接赋值
+    try {
+      localStorage.setItem(localStorageKey, lang); // 持久化到 localStorage
+      console.log(`[i18n] Locale set to "${lang}" and saved to localStorage.`); // 添加日志
+    } catch (e) {
+      console.error('[i18n] Failed to save locale to localStorage:', e);
+    }
+  } else {
+    console.warn(`[i18n] Locale "${lang}" is not available.`);
+  }
+};
+
+
 export default i18n;