.

components/ui/language-switcher.tsx

@@ -23,6 +23,10 @@ export function LanguageSwitcher() {
 
   const handleChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
     const newLocale = e.target.value
+
+    // ✅ 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)

components/utility/home-redirector.tsx

@@ -14,18 +14,21 @@ export default function HomeRedirector() {
   useEffect(() => {
     const preferred = localStorage.getItem('preferred-language')
     const currentPath = window.location.pathname
-
+  
     console.log('[HomeRedirector] preferred:', preferred)
     console.log('[HomeRedirector] currentPath:', currentPath)
-
+  
     if (!preferred || !isValidLocale(preferred)) {
       console.log('[HomeRedirector] No valid preferred language found.')
       return
     }
-
+  
+    // ✅ 同步写入 cookie
+    document.cookie = `preferred-language=${preferred}; path=/; max-age=31536000` // 1 年
+  
     const pathLocale = currentPath.split('/')[1]
     const hasLocaleInPath = isValidLocale(pathLocale)
-
+  
     if (!hasLocaleInPath) {
       const newPath = `/${preferred}${currentPath}`
       console.log('[HomeRedirector] Redirecting to:', newPath)
@@ -34,6 +37,7 @@ export default function HomeRedirector() {
       console.log('[HomeRedirector] Already has valid locale in path, skipping redirect.')
     }
   }, [])
+  
 
   return null
 }