ERP/ERP.Framework/Extensions/I18NExtension.cs

// <author></author>
// <date></date>
// <description></description>

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Localization;
using System.Globalization;

namespace ERP.Framework.Extensions
{
    public static class I18NExtension
    {
        public static void UseI18N(this IApplicationBuilder app)
        {
            app.UseRequestLocalization(options =>
            {
                var supporttedCultures = new List<CultureInfo>
                {
                    new CultureInfo("en-US"),
                    new CultureInfo("zh-CN"),
                };
                options.DefaultRequestCulture = new RequestCulture("en-US");
                options.SupportedCultures = supporttedCultures;
                options.SupportedUICultures = supporttedCultures;
                options.RequestCultureProviders = new List<IRequestCultureProvider>
                {
                    new LangCultrueProvider(),
                };
            });
        }
    }

    public class LangCultrueProvider : RequestCultureProvider
    {
        /// <inheritdoc />
        public override Task<ProviderCultureResult?> DetermineProviderCultureResult(HttpContext httpContext)
        {
            if (httpContext == null)
            {
                throw new ArgumentNullException(nameof(httpContext));
            }

            var lang = httpContext.Request.Headers["lang"].ToString();

            if (!lang.IsNullOrEmpty())
            {
                return Task.FromResult<ProviderCultureResult?>(new ProviderCultureResult(lang));
            }

            return NullProviderCultureResult;
        }
    }
}