Get `pageLanguage` from `CurrentUICulture`.

modules/docs/src/Volo.Docs.Web/DocsWebGoogleTranslationOptions.cs

@@ -1,4 +1,6 @@
+using System;
 using System.Collections.Generic;
+using System.Globalization;
 
 namespace Volo.Docs;
 
@@ -11,6 +13,8 @@ public class DocsWebGoogleTranslationOptions
     /// </summary>
     public List<string> IncludedLanguages { get; set; }
 
+    public Func<CultureInfo, string> GetCultureLanguageCode { get; set; }
+
     public DocsWebGoogleTranslationOptions()
     {
         UseGoogleTranslation = false;
@@ -34,5 +38,14 @@ public class DocsWebGoogleTranslationOptions
             "de",
             "es"
         ];
+        GetCultureLanguageCode = culture =>
+        {
+            return culture.Name switch
+            {
+                "zh-Hans" => "zh-CN",
+                "zh-Hant" => "zh-TW",
+                _ => culture.TwoLetterISOLanguageName
+            };
+        };
     }
 }

modules/docs/src/Volo.Docs.Web/Pages/Documents/Project/Index.cshtml

@@ -1,4 +1,5 @@
 @page
+@using System.Globalization
 @using Microsoft.AspNetCore.Mvc.Localization
 @using Microsoft.AspNetCore.Mvc.TagHelpers
 @using Microsoft.Extensions.Options
@@ -62,7 +63,7 @@
             <script type="text/javascript">
                 function googleTranslateElementInit() {
                     new google.translate.TranslateElement({
-                      pageLanguage: 'en',
+                      pageLanguage: '@DocsWebOptions.Value.GetCultureLanguageCode(CultureInfo.CurrentUICulture)',
                       autoDisplay: false,
                       disableAutoTranslation: true,
                       includedLanguages: '@string.Join(",", DocsWebOptions.Value.IncludedLanguages)',