Avoid setting cookies multiple times.

framework/src/Volo.Abp.AspNetCore.MultiTenancy/Volo/Abp/AspNetCore/MultiTenancy/MultiTenancyMiddleware.cs

@@ -64,6 +64,7 @@ namespace Volo.Abp.AspNetCore.MultiTenancy
                             context,
                             requestCulture
                         );
+                        context.Items[AbpRequestLocalizationMiddleware.HttpContextItemName] = true;
                     }
 
                     await next(context);

framework/src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/Localization/AbpLanguagesController.cs

@@ -33,6 +33,8 @@ namespace Volo.Abp.AspNetCore.Mvc.Localization
                 new RequestCulture(culture, uiCulture)
             );
 
+            HttpContext.Items[AbpRequestLocalizationMiddleware.HttpContextItemName] = true;
+
             var context = new QueryStringCultureReplacementContext(HttpContext, new RequestCulture(culture, uiCulture), returnUrl);
             await QueryStringCultureReplacement.ReplaceAsync(context);
 

framework/src/Volo.Abp.AspNetCore/Microsoft/AspNetCore/RequestLocalization/AbpRequestLocalizationMiddleware.cs

@@ -10,6 +10,8 @@ namespace Microsoft.AspNetCore.RequestLocalization
 {
     public class AbpRequestLocalizationMiddleware : IMiddleware, ITransientDependency
     {
+        public const string HttpContextItemName = "__AbpSetCultureCookie";
+
         private readonly IAbpRequestLocalizationOptionsProvider _requestLocalizationOptionsProvider;
         private readonly ILoggerFactory _loggerFactory;
 
@@ -29,14 +31,22 @@ namespace Microsoft.AspNetCore.RequestLocalization
                 _loggerFactory
             );
 
-            var requestCultureFeature = context.Features.Get<IRequestCultureFeature>();
-            if (requestCultureFeature?.Provider is QueryStringRequestCultureProvider)
+            context.Response.OnStarting(() =>
             {
-                AbpRequestCultureCookieHelper.SetCultureCookie(
-                    context,
-                    requestCultureFeature.RequestCulture
-                );
-            }
+                if (context.Items[HttpContextItemName] == null)
+                {
+                    var requestCultureFeature = context.Features.Get<IRequestCultureFeature>();
+                    if (requestCultureFeature?.Provider is QueryStringRequestCultureProvider)
+                    {
+                        AbpRequestCultureCookieHelper.SetCultureCookie(
+                            context,
+                            requestCultureFeature.RequestCulture
+                        );
+                    }
+                }
+
+                return Task.CompletedTask;
+            });
 
             await middleware.Invoke(context);
         }