.

components/ui/language-switcher.tsx

@@ -15,20 +15,22 @@ export function LanguageSwitcher() {
   useEffect(() => {
     if (typeof window !== 'undefined') {
       const saved = localStorage.getItem('preferred-language')
-      if (!saved || saved !== currentLocale) {
+      const isLocaleInPath = i18nConfig.locales.includes(currentLocale as any)
+
+      // ✅ 只有在 URL 中没有 locale 前缀时才写入 cookie 和 localStorage，避免错误覆盖
+      if (!isLocaleInPath && saved !== currentLocale) {
         localStorage.setItem('preferred-language', currentLocale)
+        document.cookie = `preferred-language=${currentLocale}; path=/; max-age=31536000`
+        console.log('[LanguageSwitcher] set preferred-language to:', currentLocale)
       }
     }
   }, [currentLocale])
 
   const handleChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
     const newLocale = e.target.value
-
+    document.cookie = `preferred-language=${newLocale}; path=/; max-age=31536000`
-    // ✅ 同步设置 cookie，供 middleware.ts 使用
-    document.cookie = `preferred-language=${newLocale}; path=/; max-age=31536000` // 保存 1 年
 
     let segments = pathname === '/' ? [] : pathname.split('/').filter(Boolean)
-
     const isLocaleInPath = i18nConfig.locales.includes(segments[0] as any)
 
     if (isLocaleInPath) {
@@ -39,8 +41,7 @@ export function LanguageSwitcher() {
 
     const newPath = '/' + segments.join('/')
 
-
+    // ✅ 延迟跳转，确保 cookie 写入完成
-    // 🔥 核心修复：延迟 router.push，确保 cookie 写入完成再跳转
     setTimeout(() => {
       startTransition(() => {
         if (pathname !== newPath) {
@@ -50,8 +51,6 @@ export function LanguageSwitcher() {
         }
       })
     }, 0)
-
-
   }
 
   return (