.

components/ui/language-switcher.tsx

@@ -15,24 +15,32 @@ export function LanguageSwitcher() {
   useEffect(() => {
     if (typeof window !== 'undefined') {
       const saved = localStorage.getItem('preferred-language')
+      console.log('[LanguageSwitcher] currentLocale:', currentLocale)
+      console.log('[LanguageSwitcher] saved preferred-language:', saved)
+
       if (!saved || saved !== currentLocale) {
         localStorage.setItem('preferred-language', currentLocale)
+        console.log('[LanguageSwitcher] preferred-language updated to:', currentLocale)
       }
     }
   }, [currentLocale])
 
   const handleChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
     const newLocale = e.target.value
+    console.log('[LanguageSwitcher] User selected newLocale:', newLocale)
+    console.log('[LanguageSwitcher] Current pathname:', pathname)
 
     if (typeof window !== 'undefined') {
       localStorage.setItem('preferred-language', newLocale)
+      console.log('[LanguageSwitcher] Saved newLocale to localStorage')
     }
 
     const segments = pathname.split('/')
+    console.log('[LanguageSwitcher] Segments before change:', segments)
 
-    // ✅ 修复：类型断言 readonly -> string[]
     const localeList = [...i18nConfig.locales] as string[]
     const isLocaleInPath = localeList.includes(segments[1])
+    console.log('[LanguageSwitcher] isLocaleInPath:', isLocaleInPath)
 
     if (isLocaleInPath) {
       segments[1] = newLocale
@@ -41,6 +49,7 @@ export function LanguageSwitcher() {
     }
 
     const newPath = segments.join('/')
+    console.log('[LanguageSwitcher] Final newPath:', newPath)
 
     startTransition(() => {
       router.push(newPath)